A customer has a requirement to perform a backup each night. However, the customer has a
limited amount of time for backups to run on week nights, Monday through Friday evenings.
Which backup granularity type is recommended to meet the backup window for those nights?
A.
Incremental
B.
Cumulative
C.
Full
D.
Differential
Explanation:
Backup Granularity
Backup granularity depends on business needs and the required RTO/RPO. Based on the
granularity, backups can be categorized as full, incremental, and cumulative (or differential).
Most organizations use a combination of these three backup types to meet their backup and
recovery requirements. Figure on the slide depicts the different backup granularity levels.
Full backup is a backup of the complete data on the production volumes. A full backup copy is
created by copying the data in the production volumes to a backup storage device. It provides a
faster recovery but requires more storage space and also takes more time to back up. Incremental
backup copies the data that has changed since the last full or incremental backup, whichever has
occurred more recently. This is much faster than a full backup (because the volume of data
backed up is restricted to the changed data only) but takes longer to restore . Cumulative backup
copies the data that has changed since the last full backup. This method takes longer than an
incremental backup but is faster to restore.
Another way to implement full backup is synthetic (or constructed) backup. This method is used
when the production volume resources cannot be exclusively reserved for a backup process for
extended periods to perform a full backup. It is usually created from the most recent full backup
and all the incremental backups performed after that full backup. This backup is called synthetic
because the backup is not created directly from production data.
A synthetic full backup enables a full backup copy to be created offline without disrupting the I/O
operation on the production volume. This also frees up network resources from the backup
process, making them available for other production uses.
EMC E10-001 Student Resource Guide. Module 10: Backup and Archive
