Re: Running on an NFS Mounted Directory

I am looking for the best solution to have a large amount of disk storage
attached to my PostgreSQL 8.1 server. I was thinking of having a san or nas
attached device be mounted by the pg server over nfs, hence the question
about nfs performance. What other options/protocols are there to get high
performance and data integrity while having the benefit of not having the
physical storage attached to the db server?

On 4/27/06 12:55 AM, "Jim C. Nasby" <jnasby(at)pervasive(dot)com> wrote:

> On Wed, Apr 26, 2006 at 07:35:42PM -0700, Steve Wampler wrote:
>> On Wed, Apr 26, 2006 at 10:06:58PM -0400, Ketema Harris wrote:
>>> I was wondering if there were any performance issues with having a data
>>> directory that was an nfs mounted drive? Say like a SAN or NAS device? Has
>>> anyone done this before?
>>
>> My understanding is that NFS is pretty poor in performance in general,
>> so I would expect it to be particularly bad for a DB. You might run
>> some (non-DB) performance tests to get a feel for how bad it might me.
>> (Someone once told me that NFS topped out at around 12MB/s, but I don't
>> know if that's really true [they were trying to sell a competitive
>> networked filesystem]).
>>
>> In any event, you're at least limited by ethernet speeds, if not more.
>
> More importantly, the latency involved will kill commit performance. If
> it doesn't then it's likely that fsync isn't being obeyed, which means 0
> data integrity.