Vmotion between hosts require a location change for the virtual machine swapfile

[mcmiked97]

Hello,

I configured my VM so its swap file is in a separate lun, accessible by all the hosts in the cluster. Now when I try to vmotion, I get "Unable to migrate from <source host> to <dest host>: With current configurations, Vmotion between the specified hosts would require a location change for the virtual machine swapfile, but this is not supported on the source host <source host>.

Then I get a duplicate entry except the end says "...not supported on the destination host <dest host>."

I can see the .vswp file from both servers fine when I browse through the datastore, but it refuses to vmotion. Can anyone help?

[RParker]

I know what you are trying to do, in theory it sounds like a good idea, but if you know your VM's, and they have adequate memory, they won't swap, and swap files are not that high of IO anyway.

So I would keep the VM's together with their swap files, so you can avoid this issue. Avoid the urge to test this new feature. It sounds neat to have swaps on a different drive, but it's not a good idea in practice. About the only other reason to keep them segregated, is because of disk space. If you are low on space, then maybe putting them else where won't clutter up your disk space, because they are the same size allocation as the RAM of the guest.

As you can see, it's better to keep your configurations simple.

[mcmiked97]

Hi, thanks for the reply. I've since moved the swap file back, but I was trying to follow the Best Practice Guide posted by NetApp, which recommends we move the swap file to a diff LUN for NetApp snapshot purposes. By moving the swap file to a diff LUN, we can exclude that LUN when snapshotting, which reduces the amount of unncessary activity. Thanks anyway!

[RParker]

Like I said.. sounds like a good idea in THEORY, but once again no one thought to ensure this was supported both by VM Ware and by ESX setup. Obviously it doesn't work.

Netapp may be a storage leader, but they aren't exactly VM Ware experts, all they want is performance, they don't care if it is working configuration or not.

Netapp has been giving us bad information for a few weeks now, only to be refuted by some VM Ware Techs, so I won't believe everything Netapp tells you.

[mcmiked97]

Interesting. Well I switched back to keeping it stored with the VM and vmotion worked as expected. It IS easier to manage this way. Thanks

[Ken_Cline]

About the only time I would separate the swap file is in a scenario where you are using the SAN backend to replicate the entire LUN to another location. In this scenario, the limiting factor is really the network bandwidth, and if it's constrained, then moving the swap file could make all the difference in the world.

Ken Cline

Technical Director, Virtualization

Wells Landers

VMware Communities User Moderator