I’ll spoil the ending for skim readers, App Vol 2.10 requires vSphere 6.0 Update 1a or vSphere 5.5 Update 4 (not yet released) for Writeable Volume vMotion support AND you must set a environment variable on your App Volume Managers (see below).

For those with a bit more time I’ll go into more detail. If you have been using App Volumes prior to the 2.10 release you would’ve almost certainly come up against the Writeable Volume vMotion problem. This is documented in VMware KB 2116782. A typical workaround (particuarly for floating pools) was to put DRS into manual mode and to monitor the hosts for resource utilisation.

App Volumes 2.10 added vMotion support but there was a very specific caveat that many people I have spoken to have missed. Although it is clearly documented in the release notes , I’m sure we are all guilty at times of not fully reading all documentation before rolling out the update.

For vMotion support App Volumes 2.10 requires vSphere 6.0 Update 1a or vSphere 5.5 Update 4, however at the time of writing vSphere 5.5 Update 4 has not yet been released. The reason for this is App Volumes required an additional flag which needed to be implemented into vSphere which has been done in these versions.

The second requirement is a system environment variable must be added to all App Volumes managers within the App Volumes cluster to enable vMotion support. The variable is AVM_PROTECT_VOLUMES=”1″. This variable should only be set if ALL of your vSphere hosts meet the above version requirements. If you have mixed versions of hosts then we can’t guarantee that things will not break if you set this variable to enable vMotion support. Secondly if you don’t set it on all of your App Volumes Managers I am not certain of the behaviour… feel free to test in a lab, but if you want to stay in a supported configuration then set the variable on all of your servers.

So it’s excellent that App Volumes 2.10 now supports vMotion for Writeable Volumes, but be aware of the requirements before installing the update and then scratching your head.