VM Active vs. Consumed vs Actual memory usage

[jarsenea]

Hi everyone,

I'm new to vSphere and ESX but I'm a little stumped when it comes to Active/Consumed memory usage for a VM. I know what the terms mean (Active is supposed to be the actual memory a VM is using at any moment while consumed is the memory being consumed on the host in order to power that VM)..

The thing I can't figure out however is that each of my VMs (Windows 2003 R2 Enterprise) have 3GB of RAM allocated. If I go to one of my development servers, ESX shows that the VM is consuming 3132.00MB from the host and 2856.MB is active. However, if I look at the console of the VM and open task manager, Windows reports ~510mb of ram used and 2GB available.

Why the discrepency? The reason it bugs me so much is that I consistently get alarms for most of my VMs because they've past 75% of their mem usage (even though they are barely using 20% of their usage). Because of this, I attempted to increase the memory allocated to the VM to 3.5GB, but the Active just jumped from 2.8GB to 3.4GB and I still got the alarm. This is happening on most of my VMs and I can't figure out why. (They're all P2V's)

[Rumple]

Check this thread...

http://communities.vmware.com/message/1261058#1261058

[Kit Colbert]

You'll probably want to read http://www.vmworld.com/docs/DOC-2116.

btw, what application are you running in the VM?

Thanks,

Kit

[jarsenea]

kitcolbert,

Setting the Mem.AllocGuestLargePage to 0 and executing a vMotion between two hosts fixed the issue (at least temporarily). This was occuring for ALL my VMs (ranging from a ram/processor intensive Web server to a Linux server that had nothing running on it, but was still consuming 768mb of ram for some reason).

I'll set it back to 1 once this has been fixed by VMware