Home > Storage > PowerMax and VMAX > Storage Admin > Dell PowerMax and VMAX: Non-Disruptive and Minimally Disruptive Migration Best Practices and Operational Guide > Cutover and commit phase changes
This section describes the changes and new requirements in the cutover phase of an O-MDM migration.
For minimally disruptive migrations, the administrator must first shut down the application before issuing the ‘cutover’ command. The operation will make the target devices visible to the host. Any updates made to data on the target array will be replicated back to the source array through the DM replication pathway. Upon successful completion of a cutover operation, the administrator must perform a host rescan (or host reboot) and verify that new LUNs have been discovered prior to restarting the application. The application configuration would also need to be changed to use the new LUNs.
This command is used when the migration session is in the CutoverReady state. It migrates the application’s processing to run only against the target array. The following is displayed when the ‘symdm cutover’ command is issued:
symdm cutover –sid 643 –sg APP1
A DM 'Cutover' operation is
in progress for storage group 'APP1'. Please wait...
Analyze Configuration....................................................Started.
Source Array:APM00150519204
Target Array:000197900644
Analyze Configuration.....................................................Done.
Preparing Devices for Host discovery............................Started.
Cutover...........................................................................Started.
Cutover...........................................................................Done.
Preparing Devices for Host discovery............................Done.
Create Masking View(s) on Target................................Started.
Create Masking View(s) on Target................................Done.
The DM 'Cutover' operation successfully executed for
storage group 'APP1'.
This command completes the migration by removing application resources from the source array and releasing resources used for the migration. The following is displayed when the ‘symdm commit’ command is issued:
symdm commit –sid 643 –sg DM_APP1
Analyze Configuration..............................................Started.
Source Array:APM00150519204
Target Array:000197900644
Analyze Configuration..............................................Done.
Remove Data Replication........................................Started.
Remove Data Replication........................................Done.
The DM 'Commit' operation successfully executed for
storage group 'APP1'.