Storage system with snapshot generation and/or preservation control responsive to monitored replication data
A storage system in one embodiment comprises a plurality of storage devices and a storage controller. The storage system is configured to participate as a target storage system in a replication process with a source storage system. In conjunction with the replication process, the target storage system is configured to receive from the source storage system replication data for at least one storage volume subject to replication from the source storage system to the target storage system, to generate a first snapshot for the storage volume, to monitor additional replication data received from the source storage system for the storage volume after generation of the first snapshot, and responsive to the monitored additional replication data satisfying one or more specified conditions, to perform at least one of the following operations: (i) generating a subsequent snapshot for the storage volume; and (ii) marking the first snapshot with a priority indicator.
1. An apparatus comprising:
a storage system comprising a plurality of storage devices and a storage controller;
the storage system comprising a processor and a memory coupled to the processor and being configured to participate as a target storage system in a replication process with a source storage system;
in conjunction with the replication process, the target storage system being configured:
to receive from the source storage system replication data for at least one storage volume subject to replication from the source storage system to the target storage system;
to generate a first snapshot for the storage volume;
to monitor additional replication data received from the source storage system for the storage volume after generation of the first snapshot; and
responsive to the monitored additional replication data satisfying one or more specified conditions, to perform the following operations:
(i) generating a subsequent snapshot for the storage volume; and
(ii) marking the first snapshot with a priority indicator;
wherein marking the first snapshot with a priority indicator comprises:
marking the first snapshot with a first priority indicator indicating a relatively high priority level responsive to an amount of data written to the storage volume since generation of the first snapshot exceeding a threshold; and
marking the first snapshot with a second priority indicator different than the first priority indicator, the second priority indicator indicating a relatively low priority level, responsive to the amount of data written to the storage volume since generation of the first snapshot being at or below the threshold.
2. The apparatus of claim 1 wherein the replication process comprises a synchronous replication process, and the target storage system is configured to control its generation of the subsequent snapshot for the storage volume based at least in part on satisfaction of the one or more specified conditions.
3. The apparatus of claim 1 wherein the replication process comprises an asynchronous replication process, and the target storage system is configured to mark the first snapshot with a priority indicator designating that the first snapshot should be preserved by the target storage system based at least in part on satisfaction of the one or more specified conditions.
4. The apparatus of claim 1 wherein the storage volume comprises at least one logical storage volume comprising at least a portion of a physical storage space of one or more of the storage devices.
5. The apparatus of claim 1 wherein the one or more specified conditions comprise at least one condition specified in an at least partially user-defined snapshot generation and/or preservation policy for replicated storage volumes on the target storage system.
6. The apparatus of claim 1 wherein the one or more specified conditions comprise:
at least one time-based condition; and
at least one non-time-based condition;
wherein at least one of the operations (i) and (ii) is performed responsive to satisfaction of the time-based and non-time-based conditions.
7. The apparatus of claim 6 wherein the one or more time-based conditions comprise at least a specified minimum amount of elapsed time since generation of the first snapshot.
8. The apparatus of claim 1 wherein the one or more specified conditions comprise at least one non-time-based condition, the at least one non-time-based condition comprising at least one of a specified minimum number of writes to the storage volume since generation of the first snapshot and a specified minimum amount of changed data received for the storage volume since generation of the first snapshot.
9. The apparatus of claim 1 wherein the one or more specified conditions comprise a specified minimum amount of change in the storage volume relative to the first snapshot of the storage volume.
10. The apparatus of claim 9 wherein the specified minimum amount of change in the storage volume is specified in terms of at least one of:
a minimum number of storage units of the storage volume that have changed since generation of the first snapshot; and
a minimum percentage of the storage volume that has changed since generation of the first snapshot.
11. The apparatus of claim 1 wherein monitoring the additional replication data comprises maintaining a counter indicative of an amount of data in the storage volume that has been written since generation of the first snapshot.
12. The apparatus of claim 11 wherein generating the subsequent snapshot for the storage volume responsive to the monitored additional replication data satisfying one or more specified conditions comprises generating the subsequent snapshot responsive to the counter exceeding a specified threshold, and wherein the counter is reset in conjunction with the generation of the subsequent snapshot.
13. The apparatus of claim 11 wherein marking the first snapshot with a priority indicator responsive to the monitored additional replication data satisfying one or more specified conditions comprises marking the snapshot for preservation in the storage system responsive to the counter exceeding a specified threshold, and wherein the counter is reset in conjunction with the generation of the subsequent snapshot.
14. The apparatus of claim 11 wherein maintaining the counter comprises:
detecting one or more overwrites of existing data of the storage volume; and
leaving the value of the given counter unchanged responsive to each of the one or more detected overwrites.
15. A method comprising:
configuring a storage system to participate as a target storage system in a replication process with a source storage system; and
in conjunction with the replication process, the target storage system:
receiving from the source storage system replication data for at least one storage volume subject to replication from the source storage system to the target storage system;
generating a first snapshot for the storage volume;
monitoring additional replication data received from the source storage system for the storage volume after generation of the first snapshot; and
responsive to the monitored additional replication data satisfying one or more specified conditions, performing the following operations:
(i) generating a subsequent snapshot for the storage volume; and
(ii) marking the first snapshot with a priority indicator;
wherein marking the first snapshot with a priority indicator comprises:
marking the first snapshot with a first priority indicator indicating a relatively high priority level responsive to an amount of data written to the storage volume since generation of the first snapshot exceeding a threshold; and
marking the first snapshot with a second priority indicator different than the first priority indicator, the second priority indicator indicating a relatively low priority level, responsive to the amount of data written to the storage volume since generation of the first snapshot being at or below the threshold; and
wherein the method is implemented by at least one processing device comprising a processor coupled to a memory.
16. The method of claim 15 wherein the one or more specified conditions comprise:
at least one time-based condition; and
at least one non-time-based condition;
wherein at least one of the operations (i) and (ii) is performed responsive to satisfaction of the time-based and non-time-based conditions.
17. The method of claim 15 wherein the one or more specified conditions comprise at least one non-time-based condition, the at least one non-time-based condition comprising at least one of a specified minimum number of writes to the storage volume since generation of the first snapshot and a specified minimum amount of changed data received for the storage volume since generation of the first snapshot.
18. A computer program product comprising a non-transitory processor-readable storage medium having stored therein program code of one or more software programs, wherein the program code when executed by at least one processing device causes said at least one processing device:
to configure a storage system to participate as a target storage system in a replication process with a source storage system; and
in conjunction with the replication process, to configure the target storage system:
to receive from the source storage system replication data for at least one storage volume subject to replication from the source storage system to the target storage system;
to generate a first snapshot for the storage volume;
to monitor additional replication data received from the source storage system for the storage volume after generation of the first snapshot; and
responsive to the monitored additional replication data satisfying one or more specified conditions, to perform the following operations:
(i) generating a subsequent snapshot for the storage volume; and
(ii) marking the first snapshot with a priority indicator;
wherein marking the first snapshot with a priority indicator comprises:
marking the first snapshot with a first priority indicator indicating a relatively high priority level responsive to an amount of data written to the storage volume since generation of the first snapshot exceeding a threshold; and
marking the first snapshot with a second priority indicator different than the first priority indicator, the second priority indicator indicating a relatively low priority level, responsive to the amount of data written to the storage volume since generation of the first snapshot being at or below the threshold.
19. The computer program product of claim 18 wherein the one or more specified conditions comprise:
at least one time-based condition; and
at least one non-time-based condition;
wherein at least one of the operations (i) and (ii) is performed responsive to satisfaction of the time-based and non-time-based conditions.
20. The computer program product of claim 18 wherein the one or more specified conditions comprise at least one non-time-based condition, the at least one non-time-based condition comprising at least one of a specified minimum number of writes to the storage volume since generation of the first snapshot and a specified minimum amount of changed data received for the storage volume since generation of the first snapshot.