Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

We have a machine running Windows 2008 Enterprise with the Hyper-V Server role. The machine has 48 GB of RAM, and a RAID1 of just 74 GB.

The VMs are stored on a SAN.

My question is, does the Hyper-V host server itself need a big swap file for anything?

I know the recommended size of the swap file is at least 1.5 times the amount of physical memory installed, but this is more than the amount of physical disk space. I could store part of the swap file on the SAN but I'd rather not do that.

In theory, being just a VM host, the machine should be able to run without a swap file at all, but I have my doubts. Anyone with first hand experience on this?

share|improve this question
up vote 3 down vote accepted

VMware ESX admins have to pay attention to host swap file sizes because you can overcommit on memory. With Hyper-V, you can't overcommit on memory - for example, you can't take a host with 16gb of ram and start up 8 guests with 4gb of ram each. There's pros and cons to that approach. In a nutshell, though, you're right in saying it shouldn't need a host file - as long as you don't run anything on the host other than Hyper-V guests. If you remote desktop in and run things, or if you run third party backup or antivirus software on the host, you should set up a page file just to be safe. I've seen instances where people RDP into the host and run a backup software console written in Java, for example, and it needs gigs of memory in order to start & run a restore operation.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.