Re: PG over NFS

On 3/26/07, Hannes Dorbath light-at-theendofthetunnel.de |postgresql|
<...> wrote:
> There is GFS2, OCFS, DRBD, ENBD, iSCSI, AoE and a ton of other
> technologies. What on earth is the point in trying to use a DBMS over
> NFS? :)
>
> In case it's just for the fun of it, maybe consider:
> - davfs2
> - curlftpfs
>
> > However, I am primarily concerned with safety/recoverability (on sudden power loss);
>
> Well then.. forget about NFS :)

Could you offer any explanation as to why?

> What about various replication solutions
> like slony, 8.2 warm standby log shipping, mammoth replicator?

The environments involve two small devices - one with a flash disk
(the NFS server), and a slave which network-boots off that. Hence
these suggestions don't address the problem. (Would all the
alternative protocols listed at the top be able to coexist with the
described environment? Both devices must be able to boot into Linux.)

>
> > must also assume the NFS server may lose power
>
> A raid controller with battery backed cache and/or an UPS might be a
> good start. If that's not an option disable all write caches or use a
> filesystem that supports write barriers.

On 3/26/07, Peter Eisentraut peter_e-at-gmx.net |postgresql|
<...> wrote:
> Yang wrote:
> > This has been discussed before (some URLs below), but the threads
> > have unfortunately been rather free of (precise) information. I am
> > interested in getting PG running over NFS. However, I am primarily
> > concerned with safety/recoverability (on sudden power loss); I care
> > very, very little about the performance.
>
> In my experience PG over NFS works fine, except that the kernel will
> occasionally lock up under load. But that is a general NFS problem.

We've also been using PG over NFS but had not yet been concerned with
reliability in the face of failures.

Thanks,

Yang