BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT 1

Business Continuity

Section 3(chapter 8)

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 2

Section Objective

Upon completion of this section, you will be able to:• Understand the concept of information availability

and its measurement• Describe the backup/recovery purposes and

considerations• Discuss architecture and different backup/recovery

topologies• Describe local replication technologies and their

operation• Describe remote replication technologies and their

operation.

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT 3

Introduction to Business Continuity

Chapter 11

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 4

Chapter ObjectiveAfter completing this chapter, you will be able to:• Define Business Continuity and Information

Availability • Detail impact of information unavailability • Define BC measurement and terminologies• Describe BC planning process• Detail BC technology solutions

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 5

What is Business Continuity

• Business Continuity is preparing for, responding to, and recovering from an application outage that adversely affects business operations

• Business Continuity solutions address unavailability and degraded application performance

• BC is an integrated and enterprise wide process and set of activities to ensure “information availability”

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 6

What is Information Availability (IA)

• IA refers to the ability of an infrastructure to function according to business expectations during its specified time of operation

• IA can be defined in terms of three parameters:– Accessibility

• Information should be accessible at right place and to the right user

– Reliability• Information should be reliable and correct

– Timeliness• Information must be available whenever required

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 7

Causes of Information Unavailability

Disaster (<1% of Occurrences)Natural or man made

Flood, fire, earthquakeContaminated building

Unplanned Outages (20%)Failure

Database corruptionComponent failureHuman error

Planned Outages (80%)Competing workloads

Backup, reportingData warehouse extractsApplication and data restore

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 8

Impact of DowntimeLost RevenueKnow the downtime costs (per

hour, day, two days...)• Number of employees impacted (x hours out * hourly rate)

Damaged Reputation

• Customers• Suppliers• Financial markets• Banks• Business partners

Financial Performance

• Revenue recognition• Cash flow• Lost discounts (A/P)• Payment guarantees• Credit rating• Stock price

Other ExpensesTemporary employees, equipment rental, overtime costs, extra shipping costs, travel expenses...

• Direct loss• Compensatory payments• Lost future revenue• Billing losses• Investment losses

Lost Productivity

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 9

Measuring Information Availability

• MTBF: Average time available for a system or component to perform its normal operations between failures

• MTTR: Average time required to repair a failed componentIA = MTBF / (MTBF + MTTR) or IA = uptime / (uptime + downtime)

Detection

IncidentTime

Detection elapsed time

Diagnosis

Response Time

Repair

Recovery

Repair time

Restoration

Recovery Time

MTTR – Time to repair or ‘downtime’

Incident

MTBF – Time between failures or ‘uptime’

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 10

Availability Measurement – Levels of ‘9s’ Availability

% Uptime % Downtime Downtime per Year Downtime per Week

98% 2% 7.3 days 3hrs 22 min

99% 1% 3.65 days 1 hr 41 min

99.8% 0.2% 17 hrs 31 min 20 min 10 sec

99.9% 0.1% 8 hrs 45 min 10 min 5 sec

99.99% 0.01% 52.5 min 1 min

99.999% 0.001% 5.25 min 6 sec

99.9999% 0.0001% 31.5 sec 0.6 sec

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 11

BC Terminologies

• Disaster recovery– Coordinated process of restoring systems, data, and

infrastructure required to support ongoing business operations in the event of a disaster

– Restoring previous copy of data and applying logs to that copy to bring it to a known point of consistency

– Generally implies use of backup technology• Disaster restart

– Process of restarting from disaster using mirrored consistent copies of data and applications

– Generally implies use of replication technologies

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 12

BC Terminologies (Cont.)Recovery Point Objective (RPO)• Point in time to which systems

and data must be recovered after an outage

• Amount of data loss that a business can endure

Recovery Time Objective (RTO)• Time within which systems,

applications, or functions must be recovered after an outage

• Amount of downtime that a business can endure and survive

Recovery-point objective Recovery-time objective

Seconds

Minutes

Hours

Days

Weeks

Seconds

Minutes

Hours

Days

Weeks Tape Backup

Periodic Replication

Asynchronous Replication

Synchronous Replication

Tape Restore

Disk Restore

Manual Migration

Global Cluster

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 13

Business Continuity Planning (BCP) Process

• Identifying the critical business functions • Collecting data on various business processes

within those functions• Business Impact Analysis (BIA)

– Risk Analysis• Assessing, prioritizing, mitigating, and managing risk

• Designing and developing contingency plans and disaster recovery plan (DR Plan)

• Testing, training and maintenance

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 14

BC Technology Solutions

• Following are the solutions and supporting technologies that enable business continuity and uninterrupted data availability:– Single point of failure– Multi-pathing software– Backup and replication

• Backup recovery• Local replication• Remote replication

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 15

Resolving Single Points of Failure

FC Switches

Storage Array

Redundant Network

Clustered ServersRedundant Arrays

Remote Site

Redundant Ports

Redundant FC Switches

Redundant Paths

Heartbeat Connection

IP

Storage Array

Client

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 16

Multi-pathing Software

• Configuration of multiple paths increases data availability

• Even with multiple paths, if a path fails I/O will not reroute unless system recognizes that it has an alternate path

• Multi-pathing software helps to recognize and utilizes alternate I/O path to data

• Multi-pathing software also provide the load balancing• Load balancing improves I/O performance and data

path utilization

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 17

Backup and Replication • Local Replication

– Data from the production devices is copied to replica devices within the same array

– The replicas can then be used for restore operations in the event of data corruption or other events

• Remote Replication– Data from the production devices is copied to replica devices on a

remote array – In the event of a failure, applications can continue to run from the

target device• Backup/Restore

– Backup to tape has been a predominant method to ensure business continuity

– Frequency of backup is depend on RPO/RTO requirements

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 18

Chapter Summary

Key points covered in this chapter:• Importance of Business Continuity• Types of outages and their impact to businesses• Information availability measurements• Definitions of disaster recovery and restart, RPO

and RTO• Business Continuity technology solutions

overview

BC:ISMDR:BEIT:VIII:chap8:Madhu N PIIT - 19

Concept in Practice – EMC PowerPath

SERV

ERST

ORA

GE

SCSIDriver

SCSIDriver

SCSIDriver

SCSIDriver

SCSIDriver

SCSIDriver

SCSIController

SCSIController

SCSIController

SCSIController

SCSIController

SCSIController

PowerPath Host Based Software

Resides between application and SCSI device driver

Provides Intelligent I/O path management

Transparent to the application

Automatic detection and recovery from host-to-array path failures

Host Application (s)

LUNLUN

LUNLUN

Storage Network