STORAGE CONFIGURATION BEST PRACTICES FOR SAP HANA TDI ON DELL EMC UNITY STORAGE SYSTEMS
August 2017
ABSTRACT
This solution guide describes storage best practices for SAP HANA in Tailored
Data Center (TDI) deployments on Dell EMC Unity-certified enterprise storage
family systems. The solution enables customers to use Dell EMC Unity for
SAP HANA TDI deployments in a fully supported environment with their
existing data center infrastructures, providing multiple benefits.
H15220.2
SOLUTION GUIDE
Copyright
2 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
The information in this publication is provided as is. Dell Inc. makes no representations or warranties of any kind with respect to the information in this publication, and specifically disclaims implied warranties of merchantability or fitness for a particular purpose.
Use, copying, and distribution of any software described in this publication requires an applicable software license.
Copyright © 2017 Dell Inc. or its subsidiaries. All Rights Reserved. Dell, EMC, and other trademarks are trademarks of Dell Inc. or its subsidiaries. Intel, the Intel logo, the Intel Inside logo, and Xeon are trademarks of Intel Corporation in the U.S. and/or other countries. Other trademarks may be the property of their respective owners. Published in the USA 08/17. Solution Guide, H15220.2.
Dell EMC believes the information in this document is accurate as of its publication date. The information is subject to change without notice.
Contents
3 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Contents
Executive summary ....................................................................................................................... 4
Introduction ................................................................................................................................... 6
Technology overview and considerations................................................................................... 7
Storage design recommendations for Dell EMC Unity arrays for SAP HANA ........................ 16
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity ............................. 24
Accessing Unity storage from the SAP HANA nodes ............................................................... 41
Conclusion................................................................................................................................... 45
References ................................................................................................................................... 46
Executive summary
4 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Executive summary
SAP HANA is an in-memory platform that can be deployed locally (on-premises) or in the
cloud. It is a revolutionary platform that is ideally suited for performing realtime analytics
and developing and deploying realtime applications. At the core of this realtime data
platform is the SAP HANA database.
As Figure 1 shows, SAP HANA can be deployed on-premises in two different models:
Appliance model
Tailored Datacenter Integration (TDI) model
Figure 1. SAP HANA appliance model versus the TDI model (picture © SAP SE)
SAP HANA combines SAP software components that are optimized on proven hardware
provided by SAP hardware partners. An SAP HANA appliance includes integrated
storage, compute, and network components by default. The entire appliance is certified by
SAP, built by one of the SAP HANA hardware partners, and shipped to customers with all
software components preinstalled, including the operating systems and the SAP HANA
software. The TDI approach provides more flexibility than the appliance deployment
model; the SAP HANA servers must still meet the SAP HANA requirements and be
HANA-certified by SAP, but the network and storage components can be shared across
multiple applications. Customers can use their existing enterprise storage arrays and
integrate SAP HANA seamlessly into existing data center operations, such as disaster
recovery (DR), data protection, monitoring, and management, to reduce the time-to-value,
risk, and costs of an overall SAP HANA adoption.
Dell EMC™ Unity™ x50F and x00(F) all-flash and hybrid arrays meet all performance and
functional requirements for SAP HANA and are certified by SAP. This certification enables
customers to use Dell EMC Unity for SAP HANA TDI deployments in a fully supported
environment using their existing data center infrastructures.
Using the SAP HANA hardware configuration check tool (hwcct), Dell EMC performed
extensive testing on the Unity storage family systems in accordance with the SAP HANA-
HWC-ES-1.1 certification scenario. Based on the test results, this solution guide describes
Business case
Solution
overview
Executive summary
5 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
storage configuration recommendations for the Unity all-flash and hybrid arrays that meet
SAP performance requirements (specifically, the SAP HANA TDI key performance
indicators for data throughput and latency) and ensure the highest availability for
database persistence on disk.
Note: SAP recommends that TDI customers run the hwcct tool in their environment to ensure that
their specific SAP HANA TDI implementation meets the SAP performance criteria.
This solution guide describes SAP HANA TDI deployments in physical environments. If you plan to use SAP HANA in VMware virtualized environments on vSphere, see the VMware Virtualized SAP HANA with EMC Storage Solution Guide.
Customers using SAP HANA TDI on Unity arrays can:
Integrate SAP HANA into an existing data center
Use Unity shared enterprise storage to rely on already available, multisite concepts to benefit from established automation and operations processes
Transition easily from an appliance-based model to the Unity-based TDI architecture, while relying on Dell EMC services to minimize risk
Use their existing operational processes, skills, and tools and avoid the significant risks and costs associated with operational change
Use performance and scale benefits of Unity to obtain realtime insights across the business
Expect significant benefits using flash drives for the SAP HANA persistence by reducing SAP HANA startup, host auto-failover, and backup times
Dell EMC and the authors of this document welcome your feedback on the solution and
the solution documentation. Contact [email protected] with your
comments.
Authors: Donagh Keeshan, Fergal Murphy, Jarvis Zhu, Pete Shi, Aighne Kearney
Key benefits
We value your
feedback
Introduction
6 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Introduction
Before the SAP HANA TDI deployment model was available, customers who used the
appliance model experienced the following limitations:
Limited choice of servers, networks, and storage
Little knowledge and control of the critical components in the SAP HANA appliance
Inability to use existing data center infrastructure and operational procedures, resulting in higher infrastructure startup costs
Fixed sizes for SAP HANA server and storage capacities, leading to higher costs from lack of capacity and inability to respond rapidly to unexpected growth demands
This guide describes a solution that uses SAP HANA in a TDI deployment scenario on
Dell EMC Unity enterprise storage systems. This solution reduces hardware and
operational costs, lowers risks, and increases server and network vendor flexibility.
The guide provides configuration recommendations that are based on SAP requirements
for high availability and on the performance tests and results that are required to meet the
SAP key performance indicators (KPIs) for SAP HANA TDI.
This document provides the following information:
Best practices and tips for deploying the SAP HANA database on Dell EMC Unity all-flash and hybrid storage systems
Descriptions of the configuration requirements and storage design recommendations for Unity with SAP HANA
Steps for configuring Unity storage for SAP HANA using Dell EMC UnisphereTM for Unity
Detailed instructions for accessing Unity storage from the SAP HANA nodes
This guide is intended for system integrators, systems or storage administrators,
customers, partners, and members of Dell EMC professional services who must configure
a Unity all-flash or hybrid storage array to use in a TDI environment for SAP HANA.
Document
purpose
Scope
Audience
Technology overview and considerations
7 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Technology overview and considerations
Dell EMC Unity provides customers with affordable all-flash performance solutions or
cost-effective hybrid solutions by using a midrange system that is optimized for simplicity
across the storage lifecyclethat is, simple to acquire, deploy, manage, and service. The
Unity storage system is ideally suited for midsized deployments, Remote Office/Branch
Office (ROBO) locations, and cost-sensitive, mixed-workload environments. Unity storage
is designed for all-flash arrays and is available for converged deployment, as a hybrid
system, and as a software-defined virtual edition.
Figure 2 shows the Unity product family.
Figure 2. Dell EMC Unity product family
The Unity platform is offered in two different series of models, the x00(F) and the x50F.
The x00(F) series includes the Unity 300 model and scales up to the Unity 600 model.
Customers can order and configure Unity as either an all-flash or a hybrid system. The
Unity all-flash models (300F to 600F) and hybrid models (300 to 600) are identical in form
factor and connectivity, but scale correspondingly in processing and memory capabilities.
The Unity All Flash series now includes four new models that are optimized for all-flash
performance: the x50F models, starting with the 350F and scaling to the 650F. All new
models feature additional processor cores and more system memory. The system limits
change depending on the Unity model. For more information, see the Unity Technical
Documentation data and specification sheets.
Unity uses the latest technology in multicore processors, providing greater performance
capabilities. Dell EMC recommends maximizing the use of flash drives in all Unity
systems to optimize their performance potential.
Note: Unity hybrid configurations support a maximum of 50 percent total flash capacity. If you
require more than 50 percent flash capacity, consider a Unity all-flash configuration.
Table 1 provides a detailed comparison of the Unity x00(F) models.
Table 1. Unity x00(F) models compared
Model Unity 300 Unity 400 Unity 500 Unity 600
Processor Intel E5-2603 6c/1.6Ghz
Intel E5-2630 8c/2.4GHz
Intel E5-2660 10c/2.6GHz
Intel E5-2680 12c/2.5Ghz
Memory 24 GB / SP 48 GB / SP 64 GB / SP 128 GB / SP
Dell EMC Unity
system overview
Technology overview and considerations
8 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Model Unity 300 Unity 400 Unity 500 Unity 600
Max Drives 150 250 350 500
Max Capacity (Raw)
1.5 PB 2.5 PB 3.5 PB 5.0 PB
Table 2 provides a detailed comparison of the Unity x50F models
Table 2. Unity x50F models compared
Model Unity 350F Unity 450F Unity 550F Unity 650F
Processor 2*6-core, 1.7GHz 2*10-core, 2.2GHz 8c/2.4GHz
2*14-core, 2.0Hz 10c/2.6GHz
2*14-core, 2.4GHz12c/2.5Ghz
Memory 48 GB / SP 64 GB / SP 128GB / SP 256 GB / SP
Max Drives 150 250 500 1000
Max Capacity (Raw)
2.4 PB 4.0 PB 8.0 PB 16.0 PB
As a fully unified storage array, Unity offers both block and file provisioning in the same
enclosure. Disks are provisioned into storage pools that can host both block and file data.
Connectivity is offered for both block and file protocols.
Block connectivityUse iSCSI or Fibre Channel to access LUNs, consistencygroups, VMware datastores, and VMware virtual volumes.
File connectivityNetwork-attached storage (NAS) servers can hostfile systems that are accessed using server message block (SMB) sharesor network file system (NFS) shares. NAS servers can also host VMware NFSdatastores.
Traditional storage pools
All storage resources are provisioned from storage pools. A storage pool is a collection of
physical disks that are arranged into an aggregate group, with some form of RAID applied
to the disks to provide redundancy. Traditional storage pools apply RAID protection to
discrete groups of drives within the storage pool.
On a hybrid system, storage pools can consist of disks of varying types. These disks are
sorted into one of three tiers: extreme performance (flash), performance (SAS), and
capacity (NL-SAS). For hybrid systems with a fully automated storage tiering for virtual
pools (FASTTM VP) license, you can configure a storage pool to contain multiple tiers of
disks. This is known as a heterogeneous storage pool. When combined with FAST VP,
heterogeneous storage pools can provide efficient balancing of data between tiers without
requiring user intervention. Storage pools can also contain a single tier of disks; this is
known as a homogeneous storage pool.
Figure 3 shows the different storage pool configurations.
Storage
provisioning
Technology overview and considerations
9 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Figure 3. Storage pool configurations
Each tier in a storage pool can have a different RAID configuration set. Another
consideration for storage pools is the “hot spare policy.” The Unity system reserves one
spare drive per 31 drives to serve as a spare for the system. A spare drive can replace a
faulted drive in a storage pool if it matches the drive type of the faulted disk. Any unbound
drive can serve as a spare, but Unity enforces the “1 per 31” rule.
Note: Dell EMC recommends that a storage pool always has at least 10 percent free capacity to
maintain proper functioning.
Dell EMC recommends using fewer storage pools within Unity systems to reduce
complexity and increase flexibility. It might be appropriate to configure multiple storage
pools to:
Separate workloads with different I/O profiles
Separate pools where FAST cache is and is not active
Dedicate resources to meet specific performance goals
Separate resources for multitenancy
All-flash pools
All-flash pools provide the highest level of performance in Unity systems. Use an all-flash
pool when the application requires the highest storage performance at the lowest
response time. SAS Flash 3 or SAS Flash 4 drives are preferred for all-flash pools, as
they provide higher capacities and lower cost per GB.
Dell EMC recommends using only a single drive size and a single RAID width within an
all-flash pool. You can use 1.6 TB SAS Flash 3 or SAS Flash 4 drives and configure them
all with RAID 5 8+1, for example.
Hybrid pools
Hybrid pools contain more than one type of drive technology. In addition to flash drives,
hybrid pools can contain SAS or near-line SAS (NL-SAS) drives. Hybrid pools typically
provide greater capacity at a lower cost than all-flash pools, but with lower overall
performance and higher response times. Use hybrid pools for applications that do not
require consistently low response times, or that have large amounts of mostly inactive
data.
Technology overview and considerations
10 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Note: Dell EMC recommends provisioning a flash tier in hybrid pools. The minimum
recommended flash capacity is approximately five percent of the pool capacity. For more
information, see the Dell EMC Unity: Best Practices Guide.
Dynamic pools
In Unity All Flash models running OE version 4.2.x or later, all new pools created in the
Unisphere GUI are dynamic pools. New pools created in the Unisphere CLI and REST
API are dynamic pools by default.
Note: Dynamic pools are only supported on Unity All Flash models with Unity OE version 4.2 and
later. For Unity All Flash models running OE version 4.2.x or later, you can create traditional pools
using the Unisphere CLI or REST API.
Dynamic pools implement advanced RAID technology. When creating a dynamic pool in
Unisphere, the user selects the required RAID type. The RAID width is automatically
selected by the system and depends on the number of drives selected at the time of pool
creation.
Table 3 shows the relationship between the RAID type, the RAID width, and the minimum
number of drives required to create the pool. Table 3 shows only the smallest RAID
widths supported and the minimum number of drives required to create them. For
example, the smallest RAID 5 RAID width that the system supports is a 4+1. The smallest
dynamic pool created with the RAID 5 4+1 configuration is six drives. The minimum drive
count includes the number of drives specified in the RAID width, plus an extra drive to
satisfy the spare space requirements.
Table 3. RAID requirements for dynamic pools
RAID type RAID width Minimum number of
drives How it is calculated
RAID 5 4+1 6 (4+1) +1 extra drive
RAID 6 4+2 7 (4+2) +1 extra drive
RAID 1/0 1+1 3 (1+1) +1 extra drive
Note: For more information, see the Dell EMC Unity: Dynamic Pools Overview.
Unlike traditional pools, dynamic pools do not require dedicated hot spare drives. Instead,
space within each pool is reserved and can only be used to replace a failing or failed
drive. After a dynamic pool is created and the drives are partitioned into drive extents, a
number of drive extents are reserved and marked as spare space extents.
Dynamic pools have the following advantages over traditional pools:
Drives are not wasted, because there are no fixed spares. All drives in the
system can be added to a pool. This prolongs the life of the drives in the pool,
because the load is spread across additional drives.
Rebuild times are usually much faster than with traditional pools. Because spare
capacity for a dynamic pool is spread across multiple drives rather than
Technology overview and considerations
11 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
concentrated in on a single hot spare drive, more drives contribute to the
rebuilding process when a drive fails.
Pools can usually be expanded based on the capacity required. For example,
you can add one drive at a time to a dynamic pool, providing provisioning
flexibility and cost savings.
RAID protection
Unity applies RAID protection to the drives in a storage pool to protect user data against
drive failures. The available RAID types are:
RAID 1/0―Provides the highest level of performance from a given set of drive resources, with the lowest CPU requirements. Only 50 percent of the total drive capacity is usable. This RAID type is best suited for applications with fast or high processing requirements.
RAID 5―Provides the best usable capacity from a set of drive resources, but with lower overall performance and availability than RAID 1/0. RAID 5 is best suited for transaction processing.
RAID 6―Provides better availability than RAID-5 and better usable capacity
than RAID 1/0, but has the lowest performance potential of the three RAID
types. It is best suited for read-biased workloads, such as archiving and
backup to drive.
FAST VP
FAST VP is an automated feature that optimizes disk utilization. It ensures that your data
is distributed effectively across the various media types in a multi-tier pool. FAST VP
defines three tiers of drive types:
Extreme performance tierFlash disks
Performance tierSerial-attached SCSI (SAS) disks
Capacity tierNL-SAS disks
When a storage pool with multiple tiers is created on a hybrid Unity system with licensed
FAST VP, block and file resources created on that storage pool are subject to FAST VP
policies. FAST VP policies can specify where to place the initial data populated to a
storage resourcethe highest tier or the lowest tier. As the data is manipulated, FAST VP
relocates data across the tiers based on usage, as shown in Figure 4.
Technology overview and considerations
12 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Figure 4. FAST VP relocation
Data that is accessed frequently is placed on the best-performing tier, while less-
frequently accessed data is moved to the high-capacity tiers. Data relocation is at a 256
MB granularity and can be a scheduled recurring event. Combined with FAST cache and
the other multicore optimizations, FAST VP ensures that your disks are used efficiently.
Table 4 describes the FAST VP tiering policy settings, which are defined at the data-
resource level. This policy defines both the initial tier placement and the ongoing
automated tiering of data during data relocation operations. When creating a FAST VP-
enabled storage pool, use the highest available tier for the data volumes on flash and auto
tier for the log volumes on SAS.
Table 4. Tiering policy information
Tiering policy Corresponding initial tier placement Description
Start High then Auto-Tier (default)
Highest available tier Recommended setting. Sets the initial data placement to the highest-performing disks with available space, and then relocates portions of the storage resource's data based on I/O activity.
Auto-Tier Optimize for pool performance Sets the initial data placement to a system-determined optimum setting, and then relocates portions of the storage resource's data based on the storage resource's performance statistics such that data is relocated among tiers according to I/O activity.
Technology overview and considerations
13 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Tiering policy Corresponding initial tier placement Description
Highest Available Tier
Highest available tier Sets the initial data placement and subsequent data relocation (if applicable) to the highest-performing disks with available space.
Lowest Available Tier
Lowest available tier Sets the initial data placement and subsequent data relocation (if applicable) to the most cost-effective disks with available space.
The Unity platform offers a range of storage efficiency features that can help you
maximize the utilization and performance of your system. Unity’s operating environment
was built with the capability of multicore processors and their increasing scale in mind.
With the use of flash media in hybrid array configurations, FAST cache and FAST VP can
ensure that data is readily accessible and is being stored in the proper location on the
array. Lastly, host I/O limits can be implemented to manage host activity and control
“noisy neighbors.”
Multicore optimization
A set of multicore optimizations is offered on the Unity system:
Multicore cacheWith multicore cache, read and write cache space is shared and dynamically manipulated based on the read/write activity served by the system. This ensures a proper distribution of cache resources to best serve incoming requests. The arrival rates of incoming requests are tracked and weighed against the ability of the back-end disks to write the data out of cache. Based on this information, multicore cache throttles arrival rates to avoid forced flushing. Multicore cache is fully automated. No user interaction is required to enable or manipulate the cache.
Multicore RAIDMulticore RAID manages the RAID-based protection on storage pools. With multicore RAID, any unassigned disks are marked as potential spares for use in the event of a drive fault. If a drive becomes faulted, a potential spare is selected and becomes a permanent part of the RAID group. Multicore RAID can also move a disk within the physical locations of a system. For example, a disk can be moved from one enclosure to another to better balance activity between enclosures and buses. Both assigned and unassigned disks can be relocated within a five-minute window. Note that moving an assigned disk temporarily results in a degraded RAID group. Lastly, RAID 6 groups that suffer double drive failures employ a parallel rebuild to restore full redundancy as quickly as possible. Spares are selected and the rebuild process begins immediately following a drive fault.
NAS servers
NAS servers host file systems on the Unity storage system. NAS servers use virtual
interfaces to enable host connectivity to SMB, NFS, and multiprotocol file systems, as well
as VMware NFS datastores and VMware Virtual Volumes. Depending on what is enabled
on the NAS server, SMB file systems and NFS file systems can be created either
separately or in a multiprotocol configuration. File systems and virtual interfaces are
Storage
efficiency
Unity file
systems
Technology overview and considerations
14 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
isolated to a single NAS server, allowing for multitenancy over multiple NAS servers. NAS
servers are hosted on a storage processor, and automatically fail over if the SP becomes
faulted. Any associated file systems also fail over.
File systems
File systems are file-based storage resources that are hosted on NAS servers. They are
accessed through shares, which can be provisioned for SMB or NFS access, providing
access for Windows or UNIX hosts. Depending on what protocol is selected for your file
system, only shares of that type can be provisioned. For example, if an SMB file system is
created, SMB (not NFS) shares can be provisioned. To provision both SMB and NFS
shares from a file system, use a multiprotocol file system.
File systems can be extended and shrunk in size, and allocated space is automatically
taken and reclaimed based on file system usage patterns. Finally, file systems can be
configured with quotas to better regulate file system space usage. Tree quotas and user
quotas are supported on file systems, and can be used in combination.
Note: For more information about file systems, see EMC Unity: Unity File System - A Detailed
Review.
SAP HANA is an in-memory database. The data is kept in the RAM of one or multiple
SAP HANA worker hosts. All database operations (reads, inserts, updates, or deletes) are
performed in the main memory of the host. This feature differentiates SAP HANA from
traditional databases, where only a part of the data is cached in RAM and the remaining
data resides on disk.
To ensure that the SAP HANA database can always be restored to its most recent
committed state, persistent storage is used to provide a fallback in case of failure. The log
captures all changes by database transactions (redo logs), and data and undo log
information is automatically saved to disk at regular savepoints.
Scale-up versus scale-out
As an SAP-certified enterprise storage array for SAP HANA, Unity arrays can be used for
both single-host (scale-up) and multihost (scale-out) systems in TDI deployments.
In single-host environments, the database must fit into the RAM of a single server. Single-
host environments are preferred for online transaction processing (OLTP)-type workloads
such as SAP Business Suite on SAP HANA.
In multihost environments, the database tables are distributed across the RAM of multiple
servers. Multihost environments use worker and standby hosts. A worker host is an active
component that accepts and processes database requests. A standby host is a passive
component. It has all database services running, but no data in RAM. It waits for a failure
of a worker host so that it can take over its role, a process known as host auto-failover.
Because the in-memory capacity in these deployments can be quite high, scale-out SAP
HANA clusters are perfectly suited for online analytical processing (OLAP)-type workloads
with very large datasets, such as SAP Business Warehouse on SAP HANA.
HANA I/O patterns
The HANA persistent devices have different I/O patterns. See the SAP HANA Storage
Requirements White Paper for details.
SAP HANA
Technology overview and considerations
15 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Data volume
Access to the data volume is primarily random, with various block sizes from small
4 K blocks up to large 64 M blocks. The data is written asynchronously with parallel I/Os
to the data file system. During normal operations, most of the I/Os to the data file system
are writes, and data is read from the file system only during database restarts, SAP HANA
backups, host auto-failovers, or a column store table load/reload.
Log volume
Access to the log volume is primarily sequential, with various block sizes from 4K up to
1M blocks. SAP HANA keeps a 1 M buffer for the redo log in memory. When the buffer is
full, it is synchronously written to the log volume. When a database transaction is
committed before the log buffer is full, a smaller block is written to the file system.
Because data to the log volume is written synchronously, a low latency for the I/O to the
storage device is important, especially for the smaller 4 K block and 16 K block sizes.
Similar to the data volume, during normal database operations, most of the I/Os to the log
volume are writes, and data is read from the log volume only during database restarts,
high availability (HA) failover, and log backups or database recovery.
SAP HANA I/Os can be optimized for specific storage environments. See Optimizing file
I/Os after SAP HANA installation for a description of the specific optimization required for
the Unity arrays.
Since SAP introduced the TDI deployment model, two certification scenarios have been
used to test the performance of the SAP HANA persistence (data and log) and validate
that the storage array meets the SAP KPIs for bandwidth (MB/s) and latency
(microseconds): HANA-HWC-ES 1.0 and HANA-HWC-ES 1.1.
HANA-HWC-ES 1.1
With SAP HANA 1.0 SPS 10 and higher, SAP introduced a new scenario for enterprise
storage certifications. Version 1.1 now uses the underlying file system performance tool
(fsperf) for file system performance validation. With fsperf, random I/O operations required
additional resources and the KPIs could be achieved only with more disks (HDDs) or flash
disks.
The Unity all-flash and hybrid arrays for both the x00(F) and the x50F models
have been certified using HANA-HWC-ES 1.1. All configuration and scalability
recommendations in this document are based on this scenario. When re-
validating Unity all-flash and hybrid arrays at a customer site, see SAP Note
1943937: Hardware Configuration Check Tool - Central Note.
SAP HANA
certification for
Unity
Storage design recommendations for Dell EMC Unity arrays for SAP HANA
16 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Storage design recommendations for Dell EMC Unity arrays for SAP HANA
SAP HANA production systems in TDI environments must meet the SAP KPIs. The
following configuration recommendations apply to SAP HANA production systems
deployed on Unity all-flash and hybrid storage arrays:
SAN connectivity
Virtual provisioning
Unity scalability
Capacity requirements
Competing workloads
This section addresses general considerations that arise when you connect SAP HANA to
Unity arrays.
Host connectivity
The SAP HANA nodes connect to the Unity arrays through a Fibre Channel SAN. SAN
components require a minimum 8 Gb/s link speed, and the SAN topology must follow best
practices for all redundant components and links.
General SAN considerations
The connectivity, which includes host HBAs, SAN ports, switches, and array front-end
ports, requires careful planning. Unity provides multiple options for front-end connectivity
through on-board ports directly on the DPE and optional I/O modules whose configuration
must match between SPs. Fibre Channel I/O module ports use 16 Gb SFPs. 16 Gb FC is
recommended for the best performance. All Fibre Channel ports can negotiate to lower
speeds.
The SAP HANA KPIs for TDI deployments require a maximum bandwidth of 400 MB/s per
SAP HANA node. If, for example, ten nodes are connected in a SAN to a Unity array, a
total bandwidth of 4000 MB/s is required. Assuming a 16 Gb/s front-end port provides
approximately 1500 MBps bandwidth, four dedicated 16 Gb/s front-end ports are
recommended to support ten SAP HANA nodes (4 x 1500 MB/s = 6000 MB/s), two on
each SP, to facilitate high availability, load-balancing, and continued connectivity in the
event of SP failure.
While this maximum bandwidth requirement is only seen in the unlikely event that all
nodes have this requirement simultaneously, it is one of the SAP HANA certification
criteria that the storage arrays must sustain this peak workload.
This requirement does not just affect the storage front-end configuration. In the example
with ten nodes, the complete path through the SAN network must be configured to
support the maximum bandwidth also.
SAN connectivity
Storage design recommendations for Dell EMC Unity arrays for SAP HANA
17 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
HBA ports
Each HBA port (initiator) creates a path for I/Os between the host and the SAN switch,
which then continues to the Unity storage. If a host only uses a single HBA port, it will
have a single I/O path that serves all I/Os. Such a design is not advisable, because a
single path does not provide HA and also risks a potential bottleneck during high I/O
activity due to the lack of additional ports for load-balancing.
A better design provides each SAP HANA server with at least two HBA ports, preferably
on two separate HBAs. The additional ports provide more connectivity and also allow the
Linux DM-MPIO to load-balance and failover across HBA paths.
Unity storage processor connectivity for SAP HANA persistence
Unity is a unified array providing block and file connectivity. Even though file storage can
be used in an SAP HANA environment for different purposes (such as PXE-boot and
shared file systems), the SAP TDI certification of the Unity series array applies to block
Fibre Channel (FC)-attached SAP HANA persistence (data and log) only.
Special attention is required when you connect SAP HANA nodes to the front-end FC
ports of a Unity array. The Unity series provides flexible connectivity options through Dell
EMC UltraFlexTM I/O modules for both the file for NFS/SMB connectivity and the block
storage for FC and iSCSI host connectivity.
The block connectivity for the SAP HANA persistence requires the UltraFlex I/O FC
module (block only) on each storage processor with 4 x 16 GB/s FC ports. Each Unity
model supports up to two UltraFlex I/O modules per SP.
Each SAP HANA node must connect to a minimum of two FC ports on each storage
processor. Figure 5 shows the recommended FC port connectivity on an UltraFlex I/O
module on each storage processor.
Figure 5. Rear view of Unity DPE
To achieve full I/O performance for SAP HANA production deployments, implement the
following FC port requirements for a Unity array:
Dedicate FC ports to SAP HANA and do not share them with non-SAP HANA applications.
Never connect a single HBA to both ports of the same I/O module.
Balance FC ports used for SAP HANA across all available I/O modules.
Use 16 Gb/s FC ports (recommended). Neither 10 Gb/s iSCSI nor Fibre Channel over Ethernet (FCoE) have been validated for SAP HANA.
Storage design recommendations for Dell EMC Unity arrays for SAP HANA
18 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Unity arrays can use Dell EMC Virtual Provisioning™ to provide capacity to an application.
The capacity is allocated using Virtual Provisioning data devices and provided through
storage pools based on the disk technology and RAID type.
SAP HANA persistence (data and log) for production installations
For SAP HANA production installations, Dell EMC recommends using flash drives for the
SAP HANA persistence (data and log volumes) to meet the SAP HANA KPIs.
Using flash devices provides benefits for SAP HANA production installations as follows:
Sub-millisecond latencies for small block sizes on the log volume
Reduced SAP HANA startup times when data is read from the data volumeinto memory
Reduced SAP HANA host auto-failover times in scale-out deployments whena standby node takes over the data from a failed worker node
Reduced SAP HANA backup times when the backup process needs to readthe data from the data volume
RAID protection
Flash drives successfully meet the SAP HANA performance KPIs for the SAP HANA
persistence. Dell EMC recommends the following RAID protection for SAP HANA
production systems:
Traditional pools
Unity all-flash models with RAID 5 8+1 on the extreme performance tierfor both data and log devices.
Unity hybrid models use RAID 5 8+1 (flash) on the extreme performancetier for both data and log devices.
If there is not enough flash capacity available, you can use a
FAST VP enabled storage pool RAID 5 8+1 (flash) on the Extreme performance
tier for data devices and RAID 5 4+1 (SAS) on the performance tier for log
devices.
A single RAID group RAID 5 8+1 (flash), capable of supporting up to three SAPHANA nodes.
Dynamic pools
Supported with Unity OE 4.2 version or later on all-flash models
Dynamic pools use the largest RAID width possible with the number of drives
specified at the time of creation. Use RAID 5 for dynamic pools for both data and
log devices.
Virtual
provisioning
recommendations
and data services
Storage design recommendations for Dell EMC Unity arrays for SAP HANA
19 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Storage pools
Dell EMC recommends creating one storage pool for all SAP HANA data volumes and log
volumes in a Unity array when using both an all-flash and a hybrid model.
As of OE 4.2, for all-flash models, create one dynamic storage pool on the extreme performance tier (flash).
For hybrid models, create one traditional all-flash pool or (optionally) a FAST VP-enabled traditional storage pool across the performance tier (SAS) and the extreme performance tier (flash).
SAP HANA persistence for SAP HANA nonproduction installations on Unity hybrid models
Although the SAP performance KPIs do not apply to SAP HANA nonproduction
installations, those installations are still critical components in an overall SAP landscape.
Dell EMC recommends using the SAS drives for all SAP HANA nonproduction
installations on the Unity hybrid models when you provision storage.
SAP HANA installation (/hana/shared/) on Unity hybrid models
When using NAS in Unity arrays to provide the NFS share for the SAP HANA scale-out
systems, the NL-SAS or SAS drives are sufficient when you provision additional capacity
for the /hana/shared on the Unity hybrid models.
Operating system boot image on Unity hybrid models
Using the NL-SAS or SAS drives for the OS boot image on the Unity hybrid models is
sufficient.
Unity compression
In Unity OE version 4.1 and later, Unity compression is supported on THIN LUNs and can be enabled during the LUN creation process, or enabled and disabled at a later time. The storage compression rates achieved for the SAP HANA database are typically lower than for traditional databases. This is because the SAP HANA column store compresses automatically and optimizes the compression after any changes. For best performance, Dell EMC therefore recommends not enabling Unity compression for SAP HANA production installations. For more information on Unity compression, see the EMC Unity: Compression Overview White Paper.
Use Table 5 and Table 6 to estimate the initial number of SAP HANA production nodes
that can be connected. The guidelines in Table 5 and Table 6 are based on our
performance tests on a Unity 400 model and a Unity 350F model using the SAP hwcct
tool. The tests were executed without competing workloads.
The SAP HANA node numbers listed in Table 5 and Table 6 are an initial guideline to help
you determine the number of SAP HANA worker nodes that can be connected to the Unity
array for an existing or planned SAP HANA production environment. The actual number of
production SAP HANA nodes that can be connected in a customer environment might be
higher or lower, depending on the workload. In customer environments, use the SAP
HANA hwcct tool with scenario HANA-HWC-ES 1.1 to validate the SAP HANA
performance and determine the maximum number of SAP HANA hosts on a specified
storage array.
Unity scalability
Storage design recommendations for Dell EMC Unity arrays for SAP HANA
20 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Dell EMC recommends running regular SAP HANA health checks to verify the
performance of the underlying storage environment. SAP HANA configuration mini-checks
are described in the following:
SAP Note 1969700: SQL statement collection for SAP HANA
SAP Note 1999930: SAP HANA I/O Analysis
Access to these notes requires an SAP username and password.
Table 5. Unity x00(F) models scalability for HANA production systems
Model Number of SAP HANA worker nodes
Dedicated 16 GB/s FC-ports per storage processor/array
Unity 300 / Unity 300F
5 2/4
Unity 400 / Unity 400F
10 3/6
Unity 500 / Unity 500F
12 3/6
Unity 600 / Unity 600F
16 4/8
Note: We determined the scalability of other Unity x00(F) models by extrapolating the Unity 400
test results using the performance characteristics of the other models.
Table 6. Scalability of Unity x50F models for SAP HANA production systems
Model Number of SAP HANA worker nodes
Dedicated 16 GB/s FC-ports per storage processor/array
Unity 350F 6 2/4
Unity 450F 12 3/6
Unity 550F 14 4/8
Unity 650F 18 5/10
Note: We determined the scalability of other Unity x50F models by extrapolating the Unity 350F
test results using the performance characteristics of the other models.
Every SAP HANA node requires storage devices and capacity for the following:
Operating system boot image
SAP HANA installation (/hana/shared)
SAP HANA persistence (data and log)
Backup
Capacity
requirements
Storage design recommendations for Dell EMC Unity arrays for SAP HANA
21 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Note: The formulas for capacity sizing in the SAP HANA Storage Requirements White Paper are
subject to change by SAP. Always check these formulas before you determine capacity
requirements.
Operating system boot image
When the SAP HANA nodes boot from a volume on Unity (boot from SAN), the required
capacity for the operating system must be included in the overall capacity calculation for
the SAP HANA installation. Every SAP HANA node requires approximately 100 GB
capacity for the operating system. This capacity includes space for the /usr/sap/
directory.
When booting from a SAN, follow the best practices in the “Booting from SAN” section of
the Dell EMC Host Connectivity Guide for Linux.
SAP HANA installation (/hana/shared/)
To install the SAP HANA binaries, as well as the configuration files, traces, and logs,
every SAP HANA node requires access to a file system mounted under the local mount
point /hana/shared/. In an SAP HANA scale-out cluster, a single shared file system is
required and must be mounted on every node. Most SAP HANA installations use an NFS
file system for this file system. Unity all-flash and hybrid arrays can provide this file system
with the NAS option. The size of the /hana/shared/ file system can be calculated using the
latest formula in the SAP HANA Storage Requirements White Paper. Version 2.10 of this
document used the following formulas for calculation:
Single node (scale-up):
Sizeinstallation(single-node= MIN(1 x RAM; 1 TB)
Multinode (scale-out):
Sizeinstallation(scale-out) = 1 x RAM_of_worker per 4 worker nodes
SAP HANA persistence (data and log)
The SAP HANA in-memory database requires disk storage to:
Maintain the persistence of the in-memory data on disk to prevent adata loss due to a power outage and to allow a host auto-failover, wherea standby SAP HANA host takes over the in-memory data of a failed workerhost in scale-out installations
Log information about data changes (redo log)
Every HANA node (scale-up) or worker node (scale-out) requires two disk volumes to
save the in-memory database on disk (data) and to keep a redo log (log). The size of
these volumes depends on the anticipated total memory requirement of the database and
the RAM size of the node. To prepare the disk sizing, SAP provides several tools and
documents, as described in the SAP HANA Storage Requirements White Paper.
Version 2.10 (February 2017) of this document provides the following formulas to
calculate the size of the data volume:
Option 1: If an application-specific sizing program can be used:
Storage design recommendations for Dell EMC Unity arrays for SAP HANA
22 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Sizedata = 1.2x anticipated net disk space for data
where “net disk space” is the anticipated total memory requirement of the database plus
an additional 20 percent free space. If the database is distributed across multiple nodes in
a scale-out cluster, the “net disk space” must be divided by the number of HANA worker
nodes in the cluster. For example, if the net disk space is 2 TB and the scale-out cluster
consists of four worker nodes, then every node must be assigned a 616 GB data volume
(2 TB / 4 = 512 GB x 1.2 = 616 GB).
If the net disk space is unknown at the time of the storage sizing, EMC recommends using
the RAM size of the node plus 20 percent free space for a capacity calculation of the data
file system.
Option 2: If no application-specific sizing program is available, the recommended size of
the data volume of a given SAP HANA system is equal to the total memory required for
that system:
Sizedata = 1 x RAM
The size of the log volume depends on the RAM size of the node. The SAP HANA
Storage Requirements White Paper provides the following formulas to calculate the
minimum size of the log volume:
[systems ≤ 512GB ] Sizeredolog = 1/2 x RAM
[systems > 512GB ] Sizeredolog(min) = 512GB
Backup
HANA supports backup to a file system or use of SAP-certified third-party tools. Dell EMC
supports data protection strategies for SAP HANA backup using Dell EMC Data DomainTM
and NetWorker. Although an SAP HANA backup to an NFS file system on a Unity all-flash
or hybrid array is possible, Dell EMC does not recommend backing up the SAP HANA
database to the storage array where the primary persistence resides. If you plan to back
up SAP HANA to an NFS file system on a different Unity array, refer to the SAP HANA
Storage Requirements White Paper for details about sizing the backup file system. The
capacity depends not only on the data size and the frequency of change operations in the
database, but also on the backup generations kept on disk.
When adding workloads to the Unity system, consider the reported CPU utilization rates
as well as the capacity and IOP sizing. Brief spikes of high utilization are normal and
expected on any Unity system. The Dell EMC Unity: Best Practices Guide provides details
on sustained CPU utilization and recommended operating ranges that influence whether
the system can accept additional workloads.
In highly consolidated environments, HANA, as well as other databases and applications,
competes for storage resources. The “host I/O limits” quality of service (QoS) feature can
be used to control noisy neighbors and protect the HANA production system performance.
Host I/O limits
The ability to limit the number of IOPS serviced by the Unity system is known as host I/O
limits. Host I/O limits can be applied on LUNs, VMware vStorage VMFS datastores, and
their associated snapshots. Use host I/O limits to limit incoming host activity on the basis
Competing
workloads
Storage design recommendations for Dell EMC Unity arrays for SAP HANA
23 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
of IOPS, bandwidth, or both. You can enforce limits on individual resources, or you can
share a limit among a set of resources.
Host I/O limits can be effective in consolidated environments if an overload on the storage
resources affects the performance of more critical applications, such as SAP HANA
production installations. To protect the performance of SAP HANA production systems,
consider configuring host I/O limits on LUNs, datastores of non-SAP HANA applications,
or SAP HANA nonproduction systems to limit the total IOPs or bandwidth, which might
otherwise consume a large portion of the system’s resources.
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
24 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
The Unity internal architecture eliminates complex configurations and tuning steps. You
can use Dell EMC Unisphere for Unity to complete the integral storage configuration tasks
required to:
Create the SAP HANA hosts
Create a storage pool:
Traditional pool
Dynamic pool
Create a NAS Server
Create a file system and NFS share
Create SAP HANA volumes and map the volumes to theSAP HANA nodes
Configure FAST VP
Figure 6 shows the Unisphere for Unity interface that enables you to perform these tasks.
Figure 6. Dell EMC Unisphere for Unity
Use the step-by-step instructions in the following sections as an example.
Each SAP HANA node must have two host bus adapter (HBA) ports that are zoned to the
FC ports of the Unity I/O modules.
After the SAP HANA nodes are started, if the zoning is correct, the host initiators are
visible to the Unity module.
To create an SAP HANA host:
1. Select Access > Hosts in the left panel. The Hosts page appears.
Creating a host
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
25 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
2. To add an SAP HANA host, click the plus sign in the upper left corner and select
Host. The Add a Host screen appears.
3. Type a name for the new SAP HANA host and (optionally) a description of
the host. Click Next.
4. On the OS and Network Address page, specify a host operating system and
network address. Although the operating system information is not required, it
allows for more specific configuration and troubleshooting instructions.
The network address (name or IP address) is required to customize access to the
NFS share. Click Next.
5. On the Select iSCSI Initiators page:
If you are using iSCSI initiators, from the list of auto-discovered initiators select the iSCSI initiators the host will use to access storage resources. If you do not find the initiator you want in the list, click Create Initiator to add it manually and then select that initiator from the list of manually added initiators. Click Next.
If you are not using iSCSI initiators, click Next.
6. On the Select Fibre Channel Initiators page, from the list of auto-discovered
initiators (shown in Figure 7), select the FC initiators that the host will use to
access storage resources.
If you do not find the initiator you want in the list, click Create Initiator to add an
initiator manually, and then select it from the list of manually added initiators. Click
Next.
Figure 7. Adding a Host – Select Fibre Channel Initiators page
7. On the Review Host Configuration page, review all the information you entered
for the SAP HANA host and then click Finish to create
the host.
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
26 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
A pool is a set of disks that provide specific storage characteristics for the resources that
use them. For example, the pool configuration defines the types and capacities of the
disks in the pool. For physical deployments, the pool configuration also defines the RAID
configurations.
Dell EMC recommends creating one storage pool for all SAP HANA data volumes and log
volumes in a Unity array when you are using either an all-flash model or a hybrid model.
When using the all-flash model, create one storage pool on the extreme performance tier.
When you use the hybrid model, create one traditional all-flash pool or (optionally) a FAST
VP-enabled traditional storage pool across the performance tier (SAS) and the extreme
performance tier (flash).
Note: Traditional pools are supported on all Unity models. For Unity All Flash models running OE
version 4.2.x or later, you can only create traditional pools using the Unisphere CLI or REST API.
With Unity hybrid models, traditional pools are created in the Unisphere GUI. To create an
all-flash storage pool for provisioning the HANA persistence on the Unity hybrid model:
1. Select Storage > Pools in the left panel. The Pools page appears.
2. To add a storage pool, click the plus sign in the upper left corner. The
Create Pool screen appears.
3. Enter a name and (optionally) a description of the storage pool. Click Next.
4. On the Select Storage Tiers page (shown in Figure 8), select the required tier or
tiers for the storage pool:
Extreme performance tier Provides fast access times for resources
demanding the quickest response time. Databases can achieve their best
performance when using this tier.
Performance tierProvides high, all-round performance with consistent
response times, high throughput, and good bandwidth. This tier is appropriate for
database resources accessed centrally through a network.
Capacity tier Provides high storage capacity with generally lower performance.
This tier is appropriate for storing large amounts of primarily static data (such as
video, audio, and image files) for users and applications without strict
performance requirements.
Creating a traditional
pool
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
27 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Figure 8. Creating a pool – Select Storage Tiers page
5. Under Selected Tiers, change the RAID configuration, if required.
6. Click Next. The Select Amount of Storage page appears, as shown in Figure 9.
Note: Flash drives are required to successfully meet the SAP HANA performance KPIs for the
SAP HANA persistence. With a FAST VP-enabled traditional storage pool on the Unity hybrid
model, Dell EMC recommends using RAID 5 8+1 (flash) on the extreme performance tier for data
devices and RAID 5 4+1 (SAS) on the performance tier for log devices.
Figure 9. Creating a pool – Select Amount of Storage page
7. From the drop-down list, select the usable capacity required for the
storage pool. Click Next.
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
28 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
8. Review all the information you entered for the storage pool, as shown
in Figure 10, and then click Finish to create the storage pool.
Figure 10. Creating a pool – Review Selection page
In Unity All Flash models running OE version 4.2.x or later, all new pools created in the Unisphere GUI are dynamic pools. New pools created in the Unisphere CLI and REST API are dynamic pools by default.
Note: You cannot change the RAID type of a dynamic pool after it is created. Also, you
cannot shrink a dynamic pool or change its storage characteristics without deleting the
storage resources configured in the pool and the pool itself. You can add drives to
expand the pool.
To create a dynamic pool on All Flash models with Unity OE version 4.2 or later:
1. In the left navigation bar of the GUI, click Storage > Pools. The Pools page
appears.
2. Click the plus sign in the top left corner. The Create Pool screen appears, as
shown in Figure 11.
3. Enter a name and (optionally) a description for the new storage pool. Click Next.
Creating a dynamic
pool
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
29 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Figure 11. Create Pool page
4. On the Tiers page shown in Figure 12, select Extreme Performance Tier and RAID 5 (the default) for the dynamic pool. Click Next. The Drives page appears, as shown in Figure 12.
Figure 12. Select Storage Tiers page
5. Select the number of flash drives needed to support the amount of storage required. For example, on the 350F we selected18 flash drives to support six SAP HANA nodes. Click Next.
Figure 13. Select Amount of Storage page
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
30 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
6. On the Review Your Selections page, as shown in Figure 14, review all the information you entered for the dynamic pool.
Figure 14. Review Your Selections page
7. If you are satisfied that the information is correct, click Finish.
Each SAP HANA node requires two volumes for persistence, one for data and one for log.
To create the SAP HANA volumes:
1. Select Storage > Block in the left panel. The LUNs page appears.
2. To create a LUN, click the plus sign in the upper left corner. The
Create a LUN screen appears.
3. Enter a name and (optionally) a description of the new LUN. Click Next.
4. On the Configure Storage Characteristics page, select the pool in which
to create the LUN.
If there are multiple tiers in the storage pool, select a tiering policy and enter the
required size of the LUN, as shown in Figure 15. Click Next.
Note: The default LUN selection is THIN. Leave Compression unchecked for SAP HANA
production installations.
Creating a
volume and
mapping to the
SAP HANA node
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
31 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Figure 15. Creating a LUN – Configure Storage Characteristics screen
Note: Use SAP HANA Storage Requirements to determine the final capacity of the data and log
LUNs. In the following examples, we used 256 GB for the log LUN and 614 GB for the data LUN.
5. In the Select Host Access page, check the host that will have access to the
newly created LUN, as shown in Figure 16. Click OK.
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
32 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Figure 16. Creating a LUN – Select Host Access page
6. On the Summary page, review all the information you entered for the new LUN,
as shown in Figure 17, and then click Finish to create a LUN that is visible to the
SAP HANA host.
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
33 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Figure 17. Creating a LUN - Summary
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
34 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
FAST VP is an automated feature requiring very little manual intervention.
If sufficient flash capacity is not available, you can use a FAST VP-enabled storage pool
RAID 5 8+1 (flash) for data devices and RAID 5 4+1 (SAS) for log devices to meet the
SAP HANA performance KPIs. FAST VP enables the system to retain the most frequently
accessed or important data on fast, high-performance disks and to move the less
frequently accessed and less important data to lower-performance, cost-effective disks.
For storage pools, FAST VP:
Monitors the usage of the data in a tiered pool. Tiered pools are heterogeneous pools that are configured with multiple classes of disks (flash plus SAS or NL-SAS).
Depending on the tiering policy, uses the monitoring statistics to relocate data chunks automatically, at a 256 MB granularity, to other tiers within the pool. For
example, the Start High then Auto-Tier policy relocates data to the storage tier that is best suited for that data based on relative activity.
Performs load-balancing across the disks in tiered and non-tiered pools.
Note: FAST VP can use all supported disk types except for the SAS Flash 3 disk.
To enable FAST VP:
1. In the Unisphere GUI, click the Update System Setting in the upper right corner.
Under Software and Licenses > License Information, check that FAST VP is
licensed. If not, you must acquire a license.
2. Select Storage Configuration > FAST VP and review the settings shown in
Figure 19. You can change the Data relocation rate if required – the default
is Medium.
Enabling FAST
VP
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
35 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Figure 18. FAST VP settings
3. To modify the relocation schedule, click the Modify data relocation schedule
link. The Modify data relocation schedule page appears, as shown in
Figure 19.
Figure 19. Modifying the data relocation schedule
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
36 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
4. Ensure that the Schedule data relocation checkbox is checked, and then select
the desired time and days to perform the data relocation. Click OK, and then
Apply.
In an SAP HANA scale-out implementation, install the SAP HANA database binaries on a
shared file system that is exposed to all hosts of a system under the /hana/shared
mount point. A NAS server can provide access to the shared HANA file systems.
To create a NAS server:
1. Select Storage > File on the left side. The File page appears.
2. To create a NAS server, first click the NAS Servers link and then click the plus
sign in the upper left corner. The Create a NAS Server screen appears.
3. Enter a server name and select a pool. Click Next. The Configure NAS Server
Address page appears, as shown in Figure 20.
Figure 20. Configure NAS Server Address
4. Enter the following information for the NAS server:
Ethernet Port
IP address
Subnet Mask/Prefix Length10
Gateway
VLAN ID
Click Next. The Configure Sharing Protocols screen appears, as shown
in Figure 21.
Creating a NAS
server
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
37 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Figure 21. Configure Sharing Protocols page
5. Select the Linux/Unix shares (NFS) checkbox and enable NFSv4. Click Next.
6. (Optional) On the Unix Directory Service page, configure NIS as the UDS
for the NAS server. Click Next.
7. (Optional) On the DNS page, configure the DNS for the server. Click Next.
The Review Your Selections page shown in Figure 22 appears.
Figure 22. Review Your Selections page
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
38 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
8. If you are satisfied that the information is correct, click Finish to create the NAS
Server.
Ensure there is a NAS Server configured to support the file system that you want (NFS)
and a pool with enough available storage space.
To create a NAS server:
1. Select Storage > File in the left panel. The File page appears.
2. Click the File Systems link and then click the plus sign in the upper left corner.
The Configure the Protocols the File System Supports screen
appears.
3. Select the NAS Server that was previously configured for SAP HANA. Click Next.
The Provide a Name and Description page appears.
4. Enter a name and description for the file system. Click Next. The
Configure the File System Storage Characteristics page appears, as shown in
Figure 23.
Figure 23. Configure the File System Storage Characteristics page
5. Select the pool in which to create the file system, and then enter the size
of the file system required and the tiering policy requirements. Click Next.
The Configure the Initial Share page appears, as shown in Figure 24.
Creating a file
system and NFS
share
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
39 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Figure 24. Configure the Initial Share page
6. Check the NFS Share (Linux/Unix) and type a name for the share.
Click Next. The Configure Access page appears.
7. To allow access to hosts, click the plus symbol in the Customize access for the
following hosts page. The Select Host Access page appears, as shown in
Figure 25.
Figure 25. Select Host Access page
Configuring Unity storage for HANA using Dell EMC Unisphere for Unity
40 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
8. Select the Access Type required from the list box and check the
hosts that need access to the NFS share.
Note: For the hosts to be visible, a network address must be assigned to the host.
Click OK and then click Next. The Summary page appears, as shown in
Figure 26.
Figure 26. Summary
9. Review the information you have provided. If you are satisfied that it is correct,
click Finish. The file system and NFS share are created.
Accessing Unity storage from the SAP HANA nodes
41 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Accessing Unity storage from the SAP HANA nodes
The SAP HANA 1.0 database requires Linux SUSE SLES11 or later or Red Hat RHEL 6.5
or later on the SAP HANA nodes. The SAP HANA 2.0 database requires Linux SUSE
SLES12 (or later) or Red Hat RHEL 7.5 (or later) on the SAP HANA nodes.
To access the Unity block devices from the SAP HANA nodes, ensure that zoning is correctly configured based on SAN best practices. For more information, see the Dell EMC Host Connectivity Guide for Linux.
To access the block devices from the SAP HANA nodes, first enable native Linux
multipathing. Follow the steps described in the Dell EMC Host Connectivity Guide for
Linux to enable DM-MPIO on your operating system version. Figure 27 shows an example
of a multipath.conf file.
Figure 27. Sample multipath.conf file
The SAP HANA persistent devices are visible on an SAP HANA worker host after a
restart or a rescan (using the rescan-scsi-bus.sh command). To verify that all
devices are present and that each device has the number of active paths you configured
(as shown in Figure 28, type the following command:
Multipath –ll
Figure 28. Sample Multipath -ll
Enabling native
Linux
multipathing
(DM-MPIO)
Accessing Unity storage from the SAP HANA nodes
42 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Dell EMC uses the LUN UUID to identify the correct storage devices. To view the identifier
of a Unity LUN, go to the Volume tab in the configuration workspace in the Dell EMC
Unisphere for Unity.
Note: Linux adds a preceding ‘3’ to the storage UUID.
The XFS file system provides the best performance for both SAP HANA data and log
block devices.
To format a block device with the XFS file system, run the following command on the SAP
HANA node:
$ mkfs.xfs /dev/mapper/3600601600a503e00690f195784759af8
Note: Run this command for all block devices.
If for some reason you must expand a file system, run the xfs_growfs command on the
Linux host after you expand the volume on the Unity array.
In an SAP HANA scale-out environment with worker and standby nodes, the SAP HANA
storage connector for FC (fcClient) mounts and unmounts the devices to the SAP HANA
nodes.
In addition to mounting the devices, the storage connector also writes SCSI-3 persistent
reservations (PRs) to the devices using the Linux sg_persist command. This operation,
which is called I/O fencing, ensures that only one SAP HANA worker host has access to a
set of data and log devices at a given time.
The storage connector API is controlled in the storage section of the SAP HANA
global.ini file, as shown in Figure 29. The storage section of the file contains entries
for the block devices with optional mount options. You can run the multipath –ll
command on the SAP HANA hosts to determine the worldwide identifiers (WWIDs) of the
partition entries.
Figure 29. Sample global.ini file
XFS file system
SAP HANA
storage
connector
SAP HANA
global.ini file
Accessing Unity storage from the SAP HANA nodes
43 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
For information on the SAP HANA storage connector and how to configure the global.ini
file, see the SAP HANA Administration Guide and the SAP HANA Server Installation and
Update Guide on the SAP Help Portal.
Note: SAP HANA can only be installed on certified server hardware. The installation must be
performed by a certified HANA expert.
The base layer of HANA provides two file I/O interfaces:
SimpleFile―SimpleFile is used for small, simple I/O requests on configurationfiles, traces, and so on. It uses lightweight, platform-independent wrappersaround system calls.
FileFactory & File―The FileFactory & File I/O interface is used for huge,complex streams of I/O requests on the data and log volumes and for backupand recovery. It uses synchronous and asynchronous I/O operations.
The SAP HANA file I/O layer can be configured with configuration parameters to optimize
file I/Os for a given file system (the Linux XFS file system is used on all Dell EMC storage
LUNs for the SAP HANA persistence) and storage array
After the SAP HANA persistence is installed on Unity LUNs, set the following file I/O layer
parameters for optimal I/O processing after the initial SAP HANA installation has been
completed:
max_parallel_io_requests=128
async_read_submit=on
async_write_submit_blocks=all
SAP HANA 1.0
After the initial SAP HANA installation is complete, set the parameters by using the SAP
HANA hdbparam command as <sid>adm in the Linux shell:
# su - <sid>adm
# hdbparam –p # lists current parameter setting
# hdbparam –-paramset fileio.max_parallel_io_requests=128
# hdbparam –-paramset fileio.async_read_submit=on
# hdbparam –-paramset fileio.async_write_submit_blocks=all
SAP HANA 2.0
Starting with SAP HANA 2.0, the hdbparam command-line tool has been deprecated. Instead, the parameters are defined as normal parameters in global.ini > [fileio]. Set the parameter as follows in the global.ini file:
max_parallel_io_requests=128
Both async_read_submit=on and async_write_submit_blocks=all are set by
default during installation.
For more information, see SAP Note 2399079: Elimination of hdbparam in HANA 2 (access requires an SAP username and password).
Optimizing file
I/Os after SAP
HANA
installation
Accessing Unity storage from the SAP HANA nodes
44 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Note: The previous instructions for tuning file I/O parameters are based on SAP HANA 1.0 SPS
11 and SAP HANA 2.0 SPS01. Future SAP HANA versions might allow these parameters to be
set in configuration files. See the latest SAP HANA documentation for more information.
Conclusion
45 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
Conclusion
Using SAP HANA in TDI deployments with Dell EMC Unity enterprise storage arrays
provides many benefits, including reducing hardware and operational costs, lowering
risks, and increasing hardware vendor flexibility.
All Unity flash and hybrid arrays are certified by SAP and can be used for SAP HANA
production and nonproduction installations and for single-node or scale-out systems.
Customers can now easily transition to this new architecture using SAP HANA, while
relying on Dell EMC services to minimize risk.
During our tests with SAP HANA on Unity, we observed that:
The SAP HANA-HWC-ES 1.1 certification scenario makes higher disk configuration demands than the HANA-HWC-ES 1.0 certification.
SAP HANA production installations on Unity systems require SSDs for the SAP HANA persistence to meet the SAP HANA KPIs.
Using SSDs for the SAP HANA persistence provides the following significant benefits:
Initial array and disk configuration based on capacity without the need to take spindle count into consideration.
Reduced SAP HANA startup and host auto-failover times
Reduced SAP HANA backup times
Summary
Findings
References
46 Storage Configuration Best Practices for SAP HANA TDI on Dell EMC Unity Storage Systems
References
The following documentation on Dell EMC.com or Online Support provides additional
relevant information. Access to these documents depends on your login credentials. If you
do not have access to a document, contact your Dell EMC representative.
VMware Virtualized SAP HANA with Dell EMC Storage Solution Guide
Dell EMC Host Connectivity Guide for Linux
EMC Unity: Introduction to the Unity Platform - A Detailed Review
Dell EMC Unity: Best Practices Guide
EMC Unity: Compression Overview - White Paper
EMC Unity: Unisphere Overview
EMC Unity: NAS Capabilities - A Detailed Review
You can find the following SAP HANA documentation at:
https://help.sap.com/viewer/p/SAP_HANA_PLATFORM
SAP HANA Master Guide
SAP HANA Server Installation and Update Guide
SAP HANA Studio Installation and Update Guide
SAP HANA Administration Guide
Web resources
SAP HANA Storage Requirements
SAP HANA Appliance
SAP HANA One
SAP HANA Enterprise Cloud
SAP HANA Tailored Data Center Integration - Overview
SAP HANA Tailored Data Center Integration - FAQ
Note: The following documentation requires an SAP username and password.
SAP Note 1943937 - Hardware Configuration Check Tool - Central Note
SAP Note 1969700: SQL statement collection for SAP HANA
SAP Note 1999930: SAP HANA I/O Analysis.
SAP Note 2399079—Elimination of hdbparam in HANA 2
Dell EMC
documentation
SAP HANA
documentation