The best practices for creating clones of vVol-based VMs on a
PowerStore cluster depend on application and cluster type. The best practices also depend on how you plan to distribute VM clones.
Distributing VM clones across a multi-appliance cluster (linked or instant clones)
When linked or instant clones are created from a base VM, the
PowerStore resource balancer selects an appliance on which to create the VM and it places the config vVol on that appliance. However, the data vVol for the linked clone is created on the same appliance as the base VM.
This issue can lead to following inefficiencies:
Storage - The base VM and its VM clones only use storage on a single appliance.
I/O load - The compute for VM clones might be distributed among multiple appliances, however all I/O is directed to the single appliance hosting the storage. This issue increases the I/O load and network traffic on the appliance.
Increased fault domains - The config vVols and data vVols for VM clones are on multiple fault domains.
The best practices solution is to create a base VM on each appliance in the cluster. When creating a clone from a base VM, select the appliance with the fewest clones of the base VM.
NOTE:Distributing VM clones among appliances is typically performed when there are many clones of a base VM, such as 100 clones. If there are only a few VM clones, placing all the VM clones on a single appliance, and using the other appliances for other workloads may be sufficient.
Distributing VM clones to a new appliance in a cluster (linked or instant clones)
When an appliance is added to an existing
PowerStore cluster, VM clones are stored on the same appliance as the base VM.
This issue can lead to following inefficiencies:
Storage - The base VM and its clone only use storage on a single appliance.
I/O load - The compute for VM clones might be distributed among multiple appliances, however all I/O is directed to the single appliance hosting the storage. This issue increases the I/O load and network traffic on the appliance.
The best practices solution is to manually migrate some of the VM clones to the new appliance in the cluster.
NOTE:Migrating vVols for linked VM clones transforms them into full clones, which can lead to increased storage utilization. However, the
PowerStore cluster can compensate for this issue by using storage deduplication.