What is meant by business continuity, information availability, disaster recovery and recovery point objective
BC is an integrated & enterprise wide process that includes all activities that a business must perform to mitigate the impact of planned & unplanned downtime.BC entails preparing for responding to & recovering from a system outage that adversely affects business operations.It involves proative measures ,such as business impact analysis I& risk assessments ,data protection & security and reactions countermeasures,such as disaster recovery & restart ,to be invoked in the event of a failure.The goal of business continuity solution is to ensure the "information availability required to conduct vital business operations ".
2.Information Availability -
Information availability (IA) refers to the ability of the infrastructure to function according to business expextations during its specified time of operation.IA ensures that people can access information whenever they need it.Information availability can be defined with the help of reliability ,accessibility & timeline.
- Reliability -
This reflects a components ability to function without failure,under stated conditions for a specified amount of time.
- Accessibility -
This is state within which the required information is accessible at the right place ,to the right user .The period of time during when the sytem us in an accessible state is termed system options,when it is not accessible it is termed system downtime.
- Timeliners -
Defines the exact moment or the time window (a particular time of the day ,week,month & or year as specified) during which information must be accessible.For example if online access to an application is required between 8:00am & 10:00pm each day,any disreuptions to data availability outside of this time slot are not considered to affect timeliners.
3.Disaster Recovery -
Backups can be performed to address disaster recovery needs.The backup copies are used for restaring data at alternate site whe the primary site its incapacilated due to a disater.Based on RPO & RTO requirements ,organisations use different backup strategies for disaster recovery.When a tape based backup method is used as a disater recovery strategies for disaster recovery.When a tape - based backup method is used as a disater recovery strategy ,the backup tape media is shipped & stored at an offsite location.These tapes can be recalled for restoration at disater recovery site.Organisations with stringent RPO & RTO requiremtns use remmate replication technology to replicate data to a disaster recovery site.This allows organsations to bring up production systes online in a relatively short period of time in the event of disaster.
4.Recovery point Objective (RPO) -
This is the point in time to which systems & data must be recovered after an outage.It defines the amount of data loss that a business can endure.A large RTO signifies high tolerance to informed loss in a business.Based on the RPO ,organisations plan for the minimum frequency with which a backup or replica must be made.For example,if the RPO is six hours ,backups or replicas must be made atleast once in 6hours.Figure below shows various RPO's & their corresponding ideal recovery strategies.
- RPO of 24 hours -
this ensures that backups are created on an offsite tape drive every midnight.The corresponding recovery strategy is to restare data from the set of last backup tapes.
- RPO of 1 hour -
This ships database logs to the remote site energy hour.The corresponding recovery strategy is to recover the database at the point of the last log shipment.