Time based SLA compliance for disaster recovery of business critical VMS
One example method includes receiving data segments that are not already part of a full disk image of a backup, storing the data segments in storage, determining whether or not an aggregate total of data segments in the storage, that are not already part of a full disk image of a backup, equals or exceeds a threshold, when the aggregate total of data segments in the storage equals or exceeds the threshold, creating a full disk image of a backup that includes the data segments in storage, and storing the created full disk image of the backup to a recovery disk.
1. A method, comprising:
determining a number of data segments that can be processed per unit of time by a storage environment that includes storage;
determining, based on a target disaster recovery time that is a function of the number of data segments that can be processed per unit of time by the storage environment, a threshold defined as a maximum number of new or modified data segments of one or more differential backups that can be stored in storage, since a last full backup, without requiring a new full disk backup;
receiving data segments that are not already part of a full disk image of a backup;
storing the data segments in storage;
determining whether or not an aggregate total of data segments in the storage, that are not already part of a full disk image of a backup, equals or exceeds the threshold;
when the aggregate total of data segments in the storage equals or exceeds the threshold, creating a full disk image of a backup that includes the data segments in storage; and
storing the created full disk image of the backup to a recovery disk.
2. The method as recited in claim 1 , wherein the full disk image of the backup is created prior to issuance or receipt of a disaster recovery request.
3. The method as recited in claim 1 , wherein the data segments that can be processed per unit of time comprise data segments that can be located and written to a correct respective offset at a recovery disk.
4. The method as recited in claim 1 , wherein the aggregate total of data segments is either an aggregate number of data segments, or an aggregate size of the data segments.
5. The method as recited in claim 1 , wherein when the aggregate total of data segments in the storage does not equal or exceed the threshold, creation of the full disk image of the backup is omitted.
6. The method as recited in claim 1 , wherein part or all of the method is performed at a cloud storage site.
7. The method as recited in claim 1 , further comprising:
receiving a disaster recovery request that identifies a point in time (PIT) to which a VM recovery disk is to be restored;
when the closest full disk image pre-dates the PIT, writing to the recovery disk any data segments stored after the closest full disk image and before the PIT;
when the closest full disk image follows the PIT, deleting from the recovery disk any data segments that were added to the closest full disk image after the PIT; and
instantiating a recovery VM that includes the VM recovery disk.
8. The method as recited in claim 1 , wherein the threshold is defined such that a disaster recovery process involving the recovery disk is performed within a specified time limit.
9. The method as recited in claim 1 , wherein the data segments in storage that are not part of a full disk backup comprise one or more differential backups.
10. The method as recited in claim 1 , wherein the full disk backup is performed only when the aggregate total of data segments in the storage equals or exceeds the threshold.
11. A non-transitory storage medium having stored therein instructions which are executable by one or more hardware processors to perform operations comprising:
determining a number of data segments that can be processed per unit of time by a storage environment that includes storage;
determining, based on a target disaster recovery time that is a function of the number of data segments that can be processed per unit of time by the storage environment, a threshold defined as a maximum number of new or modified data segments of one or more differential backups that can be stored in storage, since a last full backup, without requiring a new full disk backup;
receiving data segments that are not already part of a full disk image of a backup;
storing the data segments in storage;
determining whether or not an aggregate total of data segments in the storage, that are not already part of a full disk image of a backup, equals or exceeds the threshold;
when the aggregate total of data segments in the storage equals or exceeds the threshold, creating a full disk image of a backup that includes the data segments in storage; and
storing the created full disk image of the backup to a recovery disk.
12. The non-transitory storage medium as recited in claim 11 , wherein the full disk image of the backup is created prior to issuance or receipt of a disaster recovery request.
13. The non-transitory storage medium as recited in claim 11 , wherein the data segments that can be processed per unit of time comprise data segments that can be located and written to a correct respective offset at a recovery disk.
14. The non-transitory storage medium as recited in claim 11 , wherein the aggregate total of data segments is either an aggregate number of data segments, or an aggregate size of the data segments.
15. The non-transitory storage medium as recited in claim 11 , wherein when the aggregate total of data segments in the storage does not equal or exceed the threshold, creation of the full disk image of the backup is omitted.
16. The non-transitory storage medium as recited in claim 11 , wherein some or all of the operations are performed at a cloud storage site.
17. The non-transitory storage medium as recited in claim 11 , wherein the operations further comprise:
receiving a disaster recovery request that identifies a point in time (PIT) to which a VM recovery disk is to be restored;
when the closest full disk image pre-dates the PIT, writing to the recovery disk any data segments stored after the closest full disk image and before the PIT;
when the closest full disk image follows the PIT, deleting from the recovery disk any data segments that were added to the closest full disk image after the PIT; and
instantiating a recovery VM that includes the VM recovery disk.
18. The non-transitory storage medium as recited in claim 11 , wherein the threshold is defined such that a disaster recovery process involving the recovery disk is performed within a specified time limit.
19. The non-transitory storage medium as recited in claim 11 , wherein the data segments in storage that are not part of a full disk backup comprise one or more differential backups.
20. The non-transitory storage medium as recited in claim 11 , wherein the full disk backup is performed only when the aggregate total of data segments in the storage equals or exceeds the threshold.