How many VMs do you have on your datastores ?  Do you know ? should you care ?

Yes, you should care, you should care because over saturated datastores can cause issues with IO and also cause scsi locks if you are using fibre.  So what is the sweet spot ?

Unfortunately it’s one of those “It Depends” situations, isn’t everything !

It depends on the type of shared storage you are using, fiber, iSCSI, NFS and also depends on the types of VMs you are using, all I can recommend is that you try and distribute your VMs evenly and try and think about the type of VMs you are putting on the same datastore, for example, if you have multiple SQL servers on the same datastore or if you have an exchange server on the same datastore as your SQL VM’s then do something out it.

Get-Datastore | Select Name, @{N="NumVM";E={@($_ |
Get-VM).Count}} | Sort Name

Example output:

Name                  NumVM

ESX01_Local       0

FC                         0

FC1                       2

NFS_1                 7