Re: Postgresql in a Virtual Machine

On Mon, 25 Nov 2013, Merlin Moncure wrote:

> On Mon, Nov 25, 2013 at 2:01 PM, Lee Nguyen <leemobile@gmail.com> wrote:
>> Hi,
>>
>> Having attended a few PGCons, I've always heard the remark from a few
>> presenters and attendees that Postgres shouldn't be run inside a VM. That
>> bare metal is the only way to go.
>>
>> Here at work we were entertaining the idea of running our Postgres database
>> on our VM farm alongside our application vm's.  We are planning to run a few
>> Postgres synchronous replication nodes.
>>
>> Why shouldn't we run Postgres in a VM?  What are the downsides? Does anyone
>> have any metrics or benchmarks with the latest Postgres?
>
> Unfortunately (and it really pains me to say this) we live in an
> increasingly virtualized world and we just have to go ahead and deal
> with it.  I work at a mid cap company and we have a zero tolerance
> policy in terms of applications targeting hardware: in short, you
> can't.  VMs have downsides: you get less performance per buck and have
> another thing to fail but the administration advantages are compelling
> especially for large environments.  Furthermore, for any size company
> it makes less sense to run your own data center with each passing day;
> the cloud providers are really bringing up their game. This is
> economic specialization at work.

being pedantic, you can get almost all the management benefits on bare metal,
and you can rent bare metal from hosting providors, cloud VMs are not the only
option. 'Cloud' makes sense if you have a very predictably spiky load and you
can add/remove machines to meet that load, but if you end up needing to have the
machines running a significant percentage of the time, dedicated boxes are
cheaper (as well as faster)

David Lang