Craig Ringer wrote:
> On 24/06/10 12:42, Iwao Shikase wrote:
>
> > In my environment, Database cluster is in NFS server.
>
> So you are mounting an nfs file system shared by "localhost" ?
>
> Why not run PostgreSQL directly on the underlying file system, rather
> than via nfs?
>
> > I guess that, In my environment, the mount options, system synchronously
> > and without cache does not need.
>
> I would still expect to lose some written data if the system crashed or
> lost power and nfs write caching was enabled. Because nfs's caching
> doesn't guarantee write ordering, this data loss would probably horribly
> corrupt your database.
>
> If you can get your NFS implementation to guarantee write ordering then
> it's quite safe to cache. Good luck proving that it's doing the right
> thing, though.
"Safe" meaning it will not corrupt your database, but you could lose
committed transactions after a server crash.
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ None of us is going to be here forever. +