On Friday 25 June 2010 02:23:17 Iwao Shikase wrote:
> Hi Roeleveld-san,
>
> Thank you for your advice. But My purpose is to test PostgreSQL
> which data cluster is in NFS server.
> As your says, Cluster Filesystem is one of answer of sharing files.
> But my company still want to use NFS server. So I want to know
> how to use PostgreSQL using NFS.
>
> By the way,The manual says, "if possible, mount NFS file systems
> synchronously (without caching) to avoid this".
>
> I want to know what means synchronously with out caching.
> In other word, which NFS options we must use follwoing the manual.
> sync ? or noac ? or both ?
>
> Thank you ,
> Iwao Shikase
Hi Shikase-san,
I am not fully familiar with all the NFS mount options.
What the manual means is that when using NFS (Or any network-file-system) is
that you need to make sure that all write-activities are done in the sequence
they are sent and also that there is no write-caching done anywhere.
In other words, both on the NFS-client and on the NFS-server side, you need to
be certain that write-caching is disabled and that all write-actions are in
sync.
I myself only use NFS for document-storage. All the storage for server-
software (Database, email,....) are all on local disks.
If I would need to store them on a different system (NAS/SAN) then I would be
using a sharing-method that exposes the raw disk, like the methods mentioned
by Craig Ringer.
What is the actual reason why your company wants to use an NFS server to store
the database-files?
If it's for backups, why not schedule backups to be written to the NFS server?
This has the added benefit of being able to easily restore and upgrade to newer
versions without too much hassle.
--
Joost Roeleveld