Essendon wrote: » - force the hypervisor to vMotion this file over too resulting in longer vMotions. - When the environment is under contention though, it may be slightly better to have it sitting on DAS storage.
Essendon wrote: » Placing it on DAS storage will: - force the hypervisor to vMotion this file over too resulting in longer vMotions. - When the environment is under contention though, it may be slightly better to have it sitting on DAS storage.
dave330i wrote: » Unless they changed this recently with share nothing vMotion, vswap file isn't vMotioned to the new host. It's recreated on the new host.
tomtom1 wrote: » But, you could configure the swap files to be stored on local disks to remove that burden from the SAN. Imagine the scenario where the VSWP files are stored on local SSD's for fast swapping to ensure memory contention isn't as big a burden. However, in doing so, you're basically providing the same functionallity as host cache.
Essendon wrote: » Which swap file are you referring to? The .vwsp file or the VM's guest OS swap file? Assuming you are talking about the .vwsp file, placing it on shared storage will: - make vMotion quicker - easier management. Create one dedicated .vswp file datastore to avoid having to replicate these files to your DR location. This file will be recreated when the VM's restarted over on the DR site, so why replicate it. Placing it on DAS storage will: - force the hypervisor to vMotion this file over too resulting in longer vMotions. - When the environment is under contention though, it may be slightly better to have it sitting on DAS storage. In addition, you need to read up on what this file's for. In one sentence, this file is for hypervisor swapping when it's under duress and in a well-designed environment, it's not normally used. I reckon this is VCP material.
Essendon wrote: » It was a little hard to follow your last post Trev and I think you've got the .vswp file and the guest OS swap mixed up?
Essendon wrote: » It's best to have the OS's page file on shared storage, gotta get ready for work and I'll hopefully write a longer response when I reach my workplace this morning. Going by your last post, it does look like you have the .vswp file and the OS page file mixed up.
Essendon wrote: » @tom - agreed, pros and cons of both, and then not everyone has the luxury of local SSD (blades).@dave - I always believed the .vwsp file was copied over during a vMotion, it does look like Maish, Duncan Epping and Frank Denneman think the same. Is there a VMware link to suggest otherwise mate?
Essendon wrote: » I'll test and report back Dave. I'll stick with the copying idea for now, here's another link that says it's copied > vXpress: Changing Swap file Location of VMware vSphere Virtual Machines
Essendon wrote: » Yeah if the VM's powered on, the .vswp file is copied over. If the VM's powered off and restarted at another host/site, the file's recreated. Puts to rest our discussion.
darkerosxx wrote: » If both hosts use the same datastore for swap, I can't see why it would do either of those things.
dave330i wrote: » It won't. On a shared datastore vmdk don't move, so nothing happens to vswap file.
