Re: Oracle datafiles on NFS mounts

Martin Haltmayer <Martin.Haltmayer_at_0800-einwahl.de> wrote:
>There is only one advice: don't use NFS-mounted datafiles in Oracle.
>
>Reason: NFS is a udp-based protocol and therefore not reliable. It *may* work
>but you are very likely to loose data. Further, locking is not controlled by
>Oracle.

NFS can be UDP based, or TCP based. The difference is only really what layer handles the retransmits of failed packets, there's no inherent difference in reliability.

Locking is more of an issue, less so in NFSv3 than v2, and it is being completely overhauled for NFSv4. If you have an OS with a competent NFS implementation, locking should be safe. Particularly with a Netapp, where (as I understand it) all data access is done over a network, and none locally. The main problem with NFS used to be some implementations didn't locally honour locks on the server that the NFS server had given to clients.

If a Netapp offers acceptable performance, I see no reason not to use one. If you trust it at all as a storage medium in a business environment, there's no reason not to use it for Oracle. Oracle isn't special, it has to perform the same system calls that every other process does.

If you still have nightmares about the dark days of NFSv2 with faulty lock managers, and thus an inherent distrust of NFS, maybe you don't want to use it. :-)

-- 
Andrew Mobbs - http://www.chiark.greenend.org.uk/~andrewm/