Subject: Re: Moving postgres 9.4 databases to new vm hosted datacenter
To: pgsql-admin@lists.postgresql.org
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From: Ron <ronljohnsonjr@gmail.com>
Message-ID: <fd87fc85-c4e6-08ae-0bfb-3dd4639ac0c4@gmail.com>
Date: Thu, 21 Feb 2019 08:41:51 -0600
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On 2/21/19 6:42 AM, Mark Steben wrote:
> Good morning,
> We are presently planning to move our 9.4 production databases from our 
> datacenter in Norfolk where they have been running on solid state hardware 
> to a datacenter run by Expedient where they will run on pre-defined vms. 
> Our manager of development has expressed concern that there may be a 
> decline in performance - we had a similar decline several years ago when 
> we attempted to switch to vms.
> My question is: is there a facility we can install on the vm where we can 
> simulate what we run on production now to approximate the load that we 
> currently run? Perhaps a read / replay of the postgres logs?

WAL replay is single-threaded, so that won't work.

A few months ago, we migrated from physical to virtual (and upgraded from 
8.4 to 9.6) without any performance drop by ensuring that the underlying ESX 
host wasn't over-provisioned.  Naturally, you'd also have to contract for 
SSDs with Expedient.

-- 
Angular momentum makes the world go 'round.