Re: running in a virtual environment

On Fri, 2010-08-27 at 08:21 -0700, David Bear wrote:
> I'm wondering what experience people have had running pg 8.x in a
> virtualized environment.

Just to be a pain, there is no 8.x. There is 8.0.x, or more specifically
the current version 8.4.x. The only reason I say this is we recently
spent way too many bytes on the inner tubes trying to have that
argument.

> Are there any best practices to follow that differen when running on
> a real metal?

You need to spec your IO higher. You take an IO hit by virtualizing and
it is significant. Considering provisioning at least 15% more IO than
you would on bare metal.

> Are there performance issue?

Just the minor IO one I mentioned.

> What virtual environment seems most friendly to pg ? Xen, VMWare,
> other?

For servers?

KVM, VMWare, Xen are all perfectly serviceable. Depends on your actual
business requirements.

> What about storage; is it best to keep the cluster in a filesystem
> that is part of the vm-image or on a mounted file system that exists
> external to the image? (in other words, a /dev/sdxx that is really
> some NAS type of device, or NFS? CIFS?)

This has to do with actual business requirements. I tend to prefer DAS
but a good SAN or NAS (iSCSI) configuration works well. I personally
would avoid anything that is just a network mount like NFS or CIFS.

Joshua D. Drake

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