Dell EMC Solutions Enabler 9.2 SRDF Family CLI User Guide

Recovering from a failed consistency group modification

Details about change operations (target CG, SRDF groups, staging area, and operation type) are stored in the SFS.

If a modifycg operation fails and all SRDF/Star sites are reachable:

Reissue the modifycg command using exactly the same parameters as the command that failed.
If the command fails again, execute the following command at the workload site:
```
symstar -cg CgName recover
```
If the workload site or any of the SRDF/Star CG sites are unreachable, specify -force:
```
symstar -cg CgName recover -force
```
The symstar recover command uses all existing information of a dynamic modifycg operation in SFS.

The recover operation either completes the unfinished steps of the dynamic modifycg operation or rolls back any tasks performed on the CG by this operation, placing the CG into its original state before failure.

In this example, re-try of the symstar modifycg -add operation run from Site A fails due to a trip event at Site C:

From Site A, issue the symstar -cg CgName query -detail command to display whether the Composite Group State is RecoveryRequired.
To display CG SampleCG:
```
symstar -cg SampleGCG query -detail
```
Issue the symstar -cg CgName recover -force command to retry the failed operation.
To retry the failed symstar modifycg -add for CG SampleCG:
```
symstar -cg SampleCG recover -force
```
Output varies depending on whether the recovery succeeds.

If the recovery succeeds, final line of output:
```
RecoverAdd..................................................Done.
```
If the recovery determines that a rollback is necessary, SRDF rolls back the operation and removes any devices added before the failure. Final line of output:
```
RecoverRollBack.............................................Done.
```