ESX Swap file/VM Page file location question

ESXi 5 Cluster
NetApp FAS3240 Cluster (Active/Active)
NFS Datastores

I'm going through the best practices documentation from NetApp concerning vSphere and Storage (TR-3749).

NetApp recommends storing the VM Swapfile on a centralized datastore for disk cost savings (snapshots and replication). This setting would be set at the host level. When going into the settings at the cluster level, VMware "recommends" saving this within the same directory as the VM.

Anyone have experience with this? As in pros and cons? I can see where this could degrade the performance of vMotion, but other than this I was looking for some input from people who have run this in production.

Also, what are your thoughts on also moving the VM's pagefile (OS) to a separate VMDK that is located on a centralized datastore as well? Same thought process here.. disk savings is nice, but don't want to introduce stability issues (if any).
LVL 1
MMRNLAITAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
If VMs start to swap, you want to put the ESX Swap and VM Page files on the fastest datastore as you can.

Swap-In functions is what causes the most performance issues.

You may want to look at consumer SSDs - 32GB just for Host Cache Configuration now supported in ESXi 5.0 for this very purpose, SSD have far better latency, between disks and RAM for Swap file usage.

Also ensure, that Pagefiles are correctly set in the VM, and for performance again, allocate on fast datastores.

Place guest’s swap file/partition on separate vdisk
• Allows you to monitor guest swap activity through virtualDisk stats

see here

http://www.virtuallyghetto.com/2011/07/how-to-automate-host-cache.html

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
MMRNLAITAuthor Commented:
We have zero contention with our cluster in regards to memory resources. I was more interested in disk cost savings in regards to replication. We have limited bandwidth to our DR site and I want to decrease our snapshot data footprint as much as possible.


But you bring up an interesting point about using SSDs. In general can we gain performance by using them for host cache?
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Yes, Increased Performance, for very little space used.

Overcoming slower latency in using traditional disk, where SSD have much better performance in this area.

SSD is just for Host Cache. So 32GB will be ample for most sites.
Big Business Goals? Which KPIs Will Help You

The most successful MSPs rely on metrics – known as key performance indicators (KPIs) – for making informed decisions that help their businesses thrive, rather than just survive. This eBook provides an overview of the most important KPIs used by top MSPs.

MMRNLAITAuthor Commented:
one more question, would there be an issue with creating one datastore for both the swapfile and pagefile on all my VMs?
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Certainly not, but make sure you do not have performance issues with it, otherwise ALL VMs will be affected.
MMRNLAITAuthor Commented:
certainly not? As in yes? or no?

=)
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
No issues, but monitor performance of the disk and datastore.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
VMware

From novice to tech pro — start learning today.