OS Disk Size Recommendations

Frequent Contributor

We've had a ticket running with Microsoft for poor performance in AVD (and other issues) for weeks now with no solution.


I did have a minor thought today about maybe part of it being linked to the OS disk.

We run D16s_v5 (16C/64GB/Standard) with P10 Premium OS disks on the hosts.


The hosts take on up to 16 users in total. Is there any concerns with that kind of load considering all the applications we run (Adobe/Quick Books/Edge/Tons of other financial items etc) with all those users? 


I can't find any documentation that states what a best practice would be for OS Disk sizing, just CPU light/medium/heavy/power

3 Replies
Hi, a P10 Disk is going to give you 500 IOPS which equates to around 31 IOPS per user, which SHOULD be enough. But that very much depends on your applications.

You can use Azure Monitor to look at the IOPS of your disk and also look at the disk queue length to check if your storage is the bottleneck.

However, you could try expand your disk to a P15 which will give you a jump to 1100 IOPS and see if that helps. You can view all the other disk types there - https://docs.microsoft.com/en-us/azure/virtual-machines/disks-types

Hope that helps!

Neil, thanks for the reply. I did find that information but it was a little vague so I didn't make the leap. I'm not even sure this is the issue as it occurs even with just 1 or 2 people on the machine. I'm assuming its one of our many applications causing a catastrophic crash and it being unrecoverable.


VM sizing guidelines for AVD are published here
Not sure what the issue you are facing is, but the doc is worth a look.