Maximizing use of storage in a data replication environment
Mechanisms for controlling access to storage volumes on the secondary storage system is provided. A determination is made as to whether a first site computing device has sent a notification of a failure condition of a first site. In response to a determination that the notification of the failure condition of the first site has not been received, secondary workloads of a second site computing device are permitted to access storage volumes on the secondary storage system. In response to a determination that the notification of the failure condition of the first site has been received, a mode of operation of the second site is modified from a normal mode of operation to a failure mode of operation. In the failure mode of operation, the storage system controller of the second site blocks at least a portion of access requests from secondary workloads of the second site computing device.
1. A method, in a data processing system comprising a storage system controller and a secondary storage system of a second site, for controlling access to storage volumes on the secondary storage system, comprising:
in response to the storage system controller receiving a notification of a failure condition of a first site, modifying a mode of operation of the storage system controller from a normal mode of operation to a failure mode of operation, wherein in the normal mode of operation, the storage system controller permits local workloads of a second site computing device to access volumes on the secondary storage system, and wherein in the failure mode of operation, the storage system controller blocks at least a portion of requests from local workloads of the second site computing device to the secondary storage system; and
in response to the storage system controller receiving a notification of a discontinuation of the failure condition of the first site, returning the mode of operation of the storage system controller to the normal mode of operation and discontinuing, by the storage system controller, the blocking of requests from local workloads of the second site computing device.
2. The method of claim 1 , wherein, in response to the failure condition of the first site occurring, a primary workload of a first site computing device is transitioned to the second site such that the primary workload accesses the secondary storage system during the failover mode of operation rather than a primary storage system associated with the first site.
3. The method of claim 1 , wherein the second storage system comprises a plurality of logical volumes, and wherein each logical volume has an associated volume attribute specifying whether the corresponding logical volume may be accessed by local workloads during the normal mode of operation.
4. The method of claim 3 , wherein at least one first logical volume in the plurality of logical volumes has a corresponding volume attribute specifying that the at least one logical volume cannot be accessed by local workloads during the normal mode of operation, and wherein at least one second logical volume in the plurality of logical volumes has a corresponding volume attribute specifying that the at least one logical volume can be accessed by local workloads during the normal mode of operation.
5. The method of claim 3 , wherein, in the failure mode of operation, the blocking, by the storage system controller, of at least a portion of access requests from the local workloads comprises blocking all requests from local workloads directed to all logical volumes of the secondary storage system.
6. The method of claim 3 , further comprising:
associating, by the storage system controller, priority values with the logical volumes in the plurality of logical volumes; and
associating second site priority values with one or more workloads in the local workloads, wherein the blocking, by the storage system controller, of at least a portion of access requests from the local workloads comprises blocking requests from the one or more workloads in the local workloads having an associated second site priority value lower than a priority value associated with a logical volume targeted by the requests.
7. The method of claim 6 , wherein modifying the mode of operation of the second site from the normal mode of operation to the failure mode of operation comprises obtaining first site priority values for at least one of workloads or logical volumes from the first site and integrating the first site priority values into the second site priority values.
8. The method of claim 7 , Wherein integrating the first site priority values comprises merging the first site priority values with the second site priority values to generate merged priority values, and applying the merged priority values to requests from the local workloads to determine which, if any, requests from workloads in the local workloads to block.
9. The method of claim 7 , wherein integrating the first site priority values comprises replacing the second site priority values with the first site priority values and applying the first site priority values to requests from the local workloads to determine which, if any requests from workloads in the local workloads to block.
10. A computer program product comprising a non-transitory computer readable storage medium having a computer readable program stored therein, wherein the computer readable program, when executed on storage system controller associated with a second site in a replication pair comprising a first site and the second site, causes the storage system controller to:
in response to the storage system controller receiving a notification of a failure condition of a first site, modify a mode of operation of the storage system controller from a normal mode of operation to a failure mode of operation, wherein in the normal mode of operation, the storage system controller permits local workloads of a second site computing device to access volumes on the secondary storage system, and wherein in the failure mode of operation, the storage system controller blocks at least a portion of requests from local workloads of the second site computing device to the secondary storage system; and
in response to the storage system controller receiving a notification of a discontinuation of the failure condition of the first site, return the mode of operation of the storage system controller to the normal mode of operation and discontinue, by the storage system controller, the blocking of requests from local workloads of the second site computing device.
11. The computer program product of claim 10 , wherein, in response to the failure condition of the first site occurring, a primary workload of a first site computing device is transitioned to the second site such that the primary workload accesses the secondary storage system during the failover mode of operation rather than a primary storage system associated with the first site.
12. The computer program product of claim 10 , wherein the second storage system comprises a plurality of logical volumes, and wherein each logical volume has an associated volume attribute specifying whether the corresponding logical volume may be accessed by local workloads during the normal mode of operation.
13. The computer program product of claim 12 , wherein at least one first logical volume in the plurality of logical volumes has a corresponding volume attribute specifying that the at least one logical volume cannot be accessed by local workloads during the normal mode of operation, and wherein at least one second logical volume in the plurality of logical volumes has a corresponding volume attribute specifying that the at least one logical volume can be accessed by local workloads during the normal mode of operation.
14. The computer program product of claim 12 , wherein, in the failure mode of operation, the blocking of the at least a portion of access requests from the local workloads comprises blocking all requests from local workloads directed to all logical volumes of the secondary storage system.
15. The computer program product of claim 12 , wherein the computer readable program further causes the storage system controller to:
associate priority values with the logical volumes in the plurality of logical volumes; and
associate second site priority values with one or more workloads in the local workloads, wherein the blocking, by the computing device, of at least a portion of access requests from the local workloads comprises blocking requests from the one or more workloads in the local workloads having an associated second site priority value lower than a priority value associated with a logical volume targeted by the requests.
16. The computer program product of claim 15 , wherein modifying the mode of operation of the storage system controller from the normal mode of operation to the failure mode of operation comprises obtaining first site priority values for at least one of workloads or logical volumes from the first site and integrating the first site priority values into the second site priority values.
17. The computer program product of claim 16 , wherein integrating the first site priority values comprises merging the first site priority values with the second site priority values to generate merged priority values, and applying the merged priority values to requests from the local workloads to determine which, if any, requests from workloads in the local workloads to block.
18. The computer program product of claim 16 , wherein integrating the first site priority values comprises replacing the second site priority values with the first site priority values and applying the first site priority values to requests from the local workloads to determine which, if any requests from workloads in the local workloads to block.
19. An apparatus, comprising:
a storage system controller of a secondary storage system in a second site in a replication pair comprising a first site and the second site; and
a memory coupled to the storage system controller, wherein the memory comprises instructions which, when executed by the storage system controller, cause the storage system controller to:
in response to the storage system controller receiving a notification of a failure condition of a first site, modify a mode of operation of the storage system controller from a normal mode of operation to a failure mode of operation, wherein in the normal mode of operation, the storage system controller permits local workloads of a second site computing device to access volumes on the secondary storage system, and wherein in the failure mode of operation, the storage system controller blocks at least a portion of requests from local workloads of the second site computing device to the secondary storage system; and
in response to the storage system controller receiving a notification of a discontinuation of the failure condition of the first site, return the mode of operation of the storage system controller to the normal mode of operation and discontinue, by the storage system controller, the blocking of requests from local workloads of the second site computing device.
20. The apparatus of claim 19 , wherein the second storage system comprises a plurality of logical volumes, and wherein each logical volume has an associated volume attribute specifying whether the corresponding logical volume may be accessed by local workloads during the normal mode of operation, wherein the instructions further cause the storage system controller to:
associate priority values with the logical volumes in the plurality of logical volumes; and
associate second site priority values with one or more workloads in the local workloads, wherein the blocking, by the storage system controller, of the at least a portion of access requests from the local workloads comprises blocking requests from the one or more workloads in the local workloads having an associated second site priority value lower than a priority value associated with a logical volume targeted by the requests.