Migration methods

Several methods can be used to migrate image mode virtual disks (VDisks) into managed mode VDisks.

In order to perform any type of migration activity on an image mode VDisk, the image mode VDisk must first be converted into a managed mode disk. The VDisk is automatically converted into a managed mode disk whenever any kind of migration activity is attempted. After the image mode to managed mode migration operation has occurred, the VDisk becomes a managed mode VDisk and is treated the same way as any other managed mode VDisk.

If the image mode disk has a partial last extent, this last extent in the image mode VDisk must be the first to be migrated. This migration is processed as a special case. After this special migration operation has occurred, the VDisk becomes a managed mode VDisk and is treated in the same way as any other managed mode VDisk. If the image mode disk does not have a partial last extent, no special processing is performed. The image mode VDisk is changed into a managed mode VDisk and is treated the same way as any other managed mode VDisk.

An image mode disk can also be migrated to another image mode disk. The image mode disk becomes managed while the migration is ongoing, but returns to image mode when the migration is complete.

You can perform the following types of migrations:

Migrate extents
Migrate a VDisk
Migrate to image mode

Note: Migration commands fail if the target or source VDisk is offline, or if there is insufficient quorum disk space to store the metadata. Correct the offline or quorum disk condition and reissue the command.

Perform the following steps to migrate VDisks:

Dedicate one MDisk group to image mode VDisks.
Dedicate one MDisk group to managed mode VDisks.
Use the migrate VDisk function to move the VDisks.