Master the Diving Catch: Storage Recovery Challenges & Prospects

Jon William Toigo

Independent Consultant and Author

Toigo Productions

Introduction and Welcome

• “Masters of the Diving Catch”

• Topics for Discussion– Fundamentals of Fielding the Ball

– How Free Agency is Wrecking the Game

– The Importance of Spring Training

• Q&A

Then…

• Early DR planning and storage recovery– Comparatively simple, “secretary-friendly”– Bolt-on to existing applications and host

platforms– 1-for-1 replacement of mainframe and DASD– 24 to 72 hour recovery timeframe

                                                                                                                                                           

                             

…and Now

• DR in the Internet Era– 7x24x365– Lots of players — heterogeneous storage

platforms supporting heterogeneous client-server hosting configurations

– Faster, harder, and…

Uglier than Ever.

Fundamentals for Fielding the Ball

• Data is a irreplaceable asset• Goal: Avoid preventable data disasters…

– Corruption of asset (security, virus protection, backups)

– Interrupted availability (fault tolerance, meshed links, effective monitoring and management)

• While minimizing impact of events that just can’t be prevented.

All Disaster Recovery Strategies Consist of…

- EITHER -• Redundancy

– Duplicating assets on a “1-for-1” or consolidated basis– Deploying redundant assets at a sufficiently distant

location to avoid regional disaster events

- OR -• Replacement

– Fielding new assets within recovery timeframe requirements

With Data, Redundancy is the Only Option…

• Restoring data from damaged media (time consuming…)

• Re-building data from original source materials (difficult or impossible…)

• Recovering storage requires copies of current or near current data, suitable data hosting platform, and pre-planned strategy

Characteristics of Many Storage Environments Raise

Challenges• Data growth is poorly managed in most shops (lack of tools, lack of time, lack of open management standards, lack of strategic planning)

• Knee-jerk acquisitions of popular storage products leads to platform heterogeneity

Free Agency is Killing the Game…Free Agency is Killing the Game…(Ask any Storage Vendor)(Ask any Storage Vendor)

Why Effective Storage Recovery Requires a Diving

Catch…• 1-for-1 replacement is increasingly costly

• Consolidation strategies are more complex– Cross-platform data re-hosting takes time– Lack of software tools for data re-hosting

requires use of tape as medium– Large (and growing) data volume calling

efficacy of tape into question in some settings

Cross-Platform Data Re-Hosting

1-for-11-for-1Storage PlatformStorage Platform

RestoralRestoral$$$$$$

ProductionProductionEnvironmentEnvironment

RecoveryRecoveryEnvironmentEnvironment

Ideal Approach

Re-host DataRe-host DataOn ConsolidatedOn Consolidated

Minimum EquipmentMinimum EquipmentConfigurationConfiguration

(e.g., Large Array or SAN)(e.g., Large Array or SAN)

ProductionProductionEnvironmentEnvironment

RecoveryRecoveryEnvironmentEnvironment

Reality

Software Tools for MirroringSoftware Tools for Mirroring(e.g., EMC SRDF)(e.g., EMC SRDF)Only Work withOnly Work with

Same-Type ArraysSame-Type Arrays

What about 3rd Party Volume Managers?

• Limited platform support

• Vicissitudes of Host-Based Mirroring

• Warranty hassles

The Continuing Need for Tape

Tape provides the Tape provides the Only ReliableOnly Reliable

means for means for Data Re-HostingData Re-Hosting

To Arrays To Arrays or Zoned Fabricsor Zoned Fabrics

FC SWOR

ProductionProductionEnvironmentEnvironment

RecoveryRecoveryEnvironmentEnvironment

Ironies…

• “Tape is dead, and SANs have killed it.” (?!?)– Tape accounted for nearly 75% of SAN deployments through

2000, and sharing tape continues to be a leading SAN deployment motivator

• “Tape is too slow for high volume, mission-critical data. You need mirroring.” (?!?)– Ignores tape automation, increasing capacity

and speed of tape drives, and multi-stream capabilities

– Ignores nature of most databases: 80% static, 20% active

– Ignores cost of mirroring

Who’s the fairest one of all?

LAN/SANLAN/SAN MAN/WANMAN/WAN

SYMMETRICALSYMMETRICALMIRROR MIRROR (LOCAL,(LOCAL,

SHORT DISTANCE,SHORT DISTANCE,LOW LATENCY)LOW LATENCY)

ASYMMETRICALASYMMETRICALMIRRORMIRROR

(REMOTE, 2(REMOTE, 2NDND PROCESS, PROCESS,DATA NOT DATA NOT

SYNCHRONIZED)SYNCHRONIZED)

Pros and Cons of Mirroring

• PRO– Fast recovery of data access– Less vulnerability to outage– Demonstrated track record– Adjustable to recovery

requirements– New technologies (e.g.,

Wave Division Multiplexing) reducing cost of WAN/MAN interconnect

• CON– Another process to monitor

– Vendor lock-in because of platform-specific mirroring software

– Three-tier configuration required to avoid latency in production applications

– High-cost solution suited only to most extreme data recovery requirements

Pros and Cons of Tape

• PRO– Media price lower than

disk– Well-designed strategy

optimized for time-to-data– Improving media

management capabilities– Low latency solutions can

be designed– Multi-streams make multi-

TB restores feasible

• CON– Tape subject to wear and

exposed to damage in transit (tape vaulting a potential solution)

– Potential conflicts with virtualization engines

– Disk prices are falling, capacities growing

– On-line data is “better” than near-line or off-line data

Facts are Facts…

• Most IT architects embracing HSM– Enabled by evolving infrastructure view of storage– Leveraging cheaper disk platforms (IDE/ATA drives), tape

or optical for “near-line” configurations– “Content Networking”

• Problems with fault tolerance through load balancing in storage fabrics remain — no silver bullets

• Server-free backup remains a holy grail– Where does the metadata go?– Lack of granularity in “bare metal” backups

                                  

                              

The Rise of Near-Line

LAN/SANLAN/SAN

SCSI/FCSCSI/FCDISK ARRAYDISK ARRAY

FORFORON-LINE/ACTIVEON-LINE/ACTIVE

STORAGESTORAGE

IDE/ATA PLATFORMSIDE/ATA PLATFORMSOROR

TAPE (OR OPTICAL)TAPE (OR OPTICAL)FOR NEAR-LINE/STATICFOR NEAR-LINE/STATIC

STORAGESTORAGE

Select hosting platformSelect hosting platformBased on data characteristicsBased on data characteristics

And cost criteriaAnd cost criteria

The Trouble with Load Balancing

User

Load Balancers

Storage Servers

Fabric Switch

DataStorage

Zone A – User Files Zone BE-mail

Zone CDatabase

Big Issue: Potential Choke Point in Tape-based Data

Restore Storage

Servers

DataStorage

“Virtualization” Engine

“Virtual Volumes”

BackupsBackups(Reads)(Reads)

FromFrom““VirtualVirtual

Volumes”Volumes”To To

TapeTapeOKOK

RestoresRestores(Writes)(Writes)

FromFromTapeTapeToTo

““VirtualVirtualVolumes”Volumes”ChokedChoked

ByBy““Virtualization”Virtualization”

softwaresoftware

Tape and “Virtualization”

• Old software RAID write penalty…again• 100+ hours to restore 1 TB of files to

virtualized environment• Concordance of backup & restore software

and “virtualization engine” (LUN aggregation software) must be tested and verified

Get to Spring Training Camp• DR landscape complicated by

burgeoning data and new technologies “When you come to a fork in the road, take it.”*

• Proactive strategies required “You can’t think and hit at the same time.”*

• Need for frequent and thorough testing underscored “You can observe a lot by watching.”*

* Storage Recovery a la Yogi Berra

The Game goes on

• True storage networks coming soon to a theater near you…

• DataCore and FalconStor pioneering platform-agnostic data re-hosting…

• Work on standards-based management continues..– De-facto (EMC)– Open (CIMOM)

Tips for Staying in the Game

• Make recoverability a key criterion/consideration when selecting components, designing applications, architecting infrastructure, etc.

• Filter through the market hype by becoming knowledgeable about technology and its limitations– SearchStorage.com– Drplanning.org

• Join and attend a DR user group: learn from peers

And remember Yogi Berra’s greatest line:And remember Yogi Berra’s greatest line:

““Baseball (like storage recovery) is 90% mental. The other half is physical.”Baseball (like storage recovery) is 90% mental. The other half is physical.”

Next Year’s Topic: Hockey Greats Discuss

Winning Virtualization Techniques (?!#@)

And look forAnd look forDisaster Recovery Planning 3/eDisaster Recovery Planning 3/e

andandThe Holy Grail of Networked Storage ManagementThe Holy Grail of Networked Storage ManagementComing from Prentice Hall PTR in Summer 2002Coming from Prentice Hall PTR in Summer 2002

For further information…For further information…