You must follow the guidelines if you use array-based replication to protect virtual machines on sites that use Storage DRS or Storage vMotion.
- Storage DRS considers the protection and the replication status of datastores while calculating placement recommendations to perform automatic or manual migration. Storage DRS checks if the datastore is replicated or not, part of a consistency group or protection group, then tags the datastore accordingly. For more information on how Site Recovery Manager handles datastore tagging, see http://kb.vmware.com/kb/2108196.
- Site Recovery Manager supports Storage DRS clusters containing datastores from different consistency groups. If you migrate a virtual machine to a datastore that is not part of a protection group, then you have to reconfigure the protection group to include that datastore.
- Site Recovery Manager supports Storage vMotion without limitation between non-replicated datastores and between replicated datastores in the same consistency group. In those cases, Storage DRS can perform automatic Storage vMotion in clusters in automatic mode, or issue recommendations for Storage vMotion in clusters in manual mode.
- Special considerations apply to Storage vMotion between a replicated and a non-replicated datastore, or between replicated datastores in different consistency groups. In those cases, Storage DRS does not automatically initiate or recommend Storage vMotion. Manually initiated Storage vMotion results in a warning detailing the possible impact.
- Do not use Storage DRS or Storage vMotion to move virtual machines regularly. Do not accept recommendations to manually move virtual machines regularly. You can move virtual machines occasionally, but excessive movement of virtual machines can cause problems. Moving virtual machines requires the array to replicate virtual machines over the network, which takes time and consumes bandwidth. When Storage DRS or Storage vMotion moves virtual machines, you might encounter problems during a recovery:
- If Storage DRS or Storage vMotion moves a virtual machine to a different consistency group within the same protection group, there is a short period between Site Recovery Manager propagating the new location of the virtual machine to the recovery site and the array replicating the changes to the recovery site. In addition, there is another period during which the arrays replicate the source and target consistency groups to a consistent state on the recovery site. While the array is propagating all of the changes to the recovery site, disaster recovery of this virtual machine might fail.
- If Storage DRS or Storage vMotion moves a virtual machine to a different protection group, Site Recovery Manager generates a protection error for this virtual machine. You must unconfigure protection of the virtual machine in the old protection group and configure protection of the virtual machine in the new protection group. Until you configure protection in the new protection group, planned migration or disaster recovery of this virtual machine fails.
- Adding a disk to a protected virtual machine results in the same problems as for moving an entire virtual machine. Site Recovery Manager does not prevent you from doing this, but if a virtual machine contains an unreplicated disk and you do not exclude the disk from protection, powering on the virtual machine fails after the move.