Memory Swap Used increasing on some ESX hosts - should I be concerned?

[JonRoderick]

Just wondering if anyone thinks I should be worried.

It suggests to me there isn't enough memory in the host to satisfy all the VM requirements and it's having to swap some out to disk - I could be wrong.

Cheers.

[weinstein5]

Which swap are you referring to? If it is the swap file used by the service console than that might be an indication that service console needs more memory - if the vm's themselves are swapping out to their individual vmkernel swap files then yes that is an indication you need more memory in your host - how are you checking the swap memory usage -

[JonRoderick]

Sorry, should have said. It's the Memory Swap Used (Average/Absolute) counter in the VC performance stats for the host itself, not individual VMs.

[Ken_Cline]

Thread moved to the Performance forum.

Host swap space used is not necessarily something to be concerned about. It could simply be memory that the guests are not actively using. To determine if there's a paging problem, check the swap rate (swapin, swapout). If there is a large number of swap operations, then you need to be concerned.

There are several good documents on monitoring system performance. I'd suggest starting with these:

- - VirtualCenter Performance Counters

- - Understanding VirtualCenter Performance Statistics

- - Memory Performance Analysis and Monitoring

And, of course, check out the list of all performance-related docs that are currently available:

- - Performance Community Documents

Good Luck!

KLC

Ken Cline

Technical Director, Virtualization

Wells Landers[/url]

VMware Communities User Moderator

[JonRoderick]

Thanks - I'll give them a read - looking at my counters, there does appear to be a large amount of swap in/out action going on - noticeably absent on other hosts that are very lightly loaded.

Cheers.