> On Mar 5, 2018, at 8:53 AM, David Gauthier <davegauthie...@gmail.com> wrote: > > Hi: > > I'm going to be requesting a PG DB instance (v9.6.7) from an IT dept in a > large corp setting. I was wondering if anyone could comment on the pros/cons > of getting this put on a virtual machine vs hard metal ? Locally mounted > disk vs nfs ?
I've been running postgresql instances on ESXi VMs for years with no issues. I've not benchmarked them, but performance has been good enough despite their running on fairly wimpy hardware. Performance relative to bare metal is probably going to be dominated by disk IO, and depending on how you're hosting VMs that can be anywhere between pretty good and terrible - in a large corporation I'd expect it to be pretty good. Just don't skimp on RAM - having your hot data in the filesystem cache is always good and can make high latency storage tolerable. If performance isn't critical then a VM is great. If it is, you'll want to plan and maybe benchmark a bit to decide whether bare metal is going to be significantly better for what you're doing. I wouldn't let NFS anywhere near it. I'd ideally want something that looks to the VM like a locally mounted disk, whether that be really local or served from a SAN or iSCSI or ... https://www.slideshare.net/jkshah/best-practices-of-running-postgresql-in-virtual-environments has some hints on VM-specific things to consider. Cheers, Steve
