Recently I’ve been sorting through VVols on vSphere 6.5 with a few storage vendors . Below are some items to be aware of as you are testing or rolling out VVols in your own environment.
Critical – Self Hosted vCenters
- Never run vCenter/PSC or any other required support VMs on VVols if it’s self-hosted. vCenter is required to be running to initiate VM power on for a vm, so you would get trapped in a circular dependency. There are ways of recovering those VVols elsewhere depending on the storage provider but you should check with them for the details.
Design and Setup
- vCenter and ESXi connectivity may require new firewall rules to the storage array management ports and/or the array controllers. For instance, Nimble Storage sets up 1 VASA Provider to the array management interface. While Pure Storage sets up a VASA Provider for each controller. Check with your storage vendor for details.
- Don’t assume a storage array can provide VVols to multiple vCenters. Each storage vendor is different so check with them first. For example, one vendor may use the existing management SSL certificate for the VASA Providers. While another may replace the SSL certificates on the array controllers with certificates generated from your own PSC which get’s complicated if you aren’t linking your vCenters.
- Some Storage Vendors use vSphere Web Client plugins to manage VASA Provider/ESXi PE setup/VVOL creation, such as Pure Storage. Nimble Storage, for example, handles setup differently by using the array itself to talk to vCenter for VASA Provider setup and ESXi extensions (Nimble Connection Manager) to setup PEs on each ESXI host. Check with your vendor on specific details.
vCenter Storage Policies
- Research and test how the vCenter storage policies interact with the array. For instance, in Nimble Storage you can create snapshot details on the vCenter policies that push into the array. Pure Storage currently does it a little different where you create snapshot policies on the array and can sync them into vCenter where they show up as an option for VM deployment if there’s more than one overlapping snapshot policy.
- If you modify a vCenter storage policy, such as enabling deduplication, you may need to migrate the VM off and back on again to get it to implement the new options. Otherwise only new VMs would get the adjusted feature set of the storage policy.
- Snapshots are handled differently on VVOls since the array can now manage how those are created or deleted. Test all of your Storage vMotion scenarios, moving VMs off and on VVols, as well as recovery methods. Check with your storage vendor to see if you need to delete VM snapshots before moving them into or out of a VVOl.