Speeding up vCenter Template Cloning

Sorry I didn't see this one when you logged it the other day, it's actually quite simple.

There's really only two modes for cloning - clone-by-host and clone-by-array.

Clone-by-host is when the host reads the template blocks and writes them back out to the new VM files. The time taken for this is heavily reliant on the speed of the network between host and array - in this case it's quite slow at 1Gbps and iSCSI adds its own overhead, obviously moving to 10/25/40Gbps would significantly increase this speed - though of course you could be limited at that level by the actual array size.

Clone-by-array is kind of simpler, the host sends some commands to the array to simply close a list of blocks, the array then gets on with the job itself. This is obviously a lot faster and reduces the impact of slower links between host and array BUT it is utterly reliant on the array supporting this kind of load. Specifically the array needs to support VMware's 'VAAI' protocols to do this. You can check for this support on VMware's Hardware Compatibility website but if your array doesn't support it then you're out of luck sorry, well unless a newer version of the software it runs suddenly starts supporting it anyway.

I hope this helps.