How many Virtual Machines per datastore, here’s something to think about August 13, 2012Posted by vbry21 in VMware blogs.
I sometimes get asked the question about how many Virtual Machines should be placed on a VMFS datastore and sorry to give a sales answer but it depends.
There are quite a few variables that need to be taken into account.
The first variable for me is what is the VM used for? If it’s a disk intensive application, then perhaps it should have its own datastore.
How is the datastore built? By that I mean how is the LUN built, a LUN built with multiple spindles will perform better that a LUN with few spindles.
How much cache does the array have? More cache means better performance.
What is the technology that the array is built on? SSD is better than 15k disks, which are better than 10k.
But, the best answer is talk to a vendor partner, they can analyse the work load and advise, talk to the SAN provider, they can advise based off the technology you buy.
If you want a ball park, then quite a few blogs and community site state 20-25 VMs, but again it depends.