I've been asked a few times whether NFS is safe for writing transaction logs. Typically, I'm told NFS is not safe and doesn't guarantee the write was really written to the disk. It completely depends on the NFS server implementation. There are NFS implementations that are certified by IBM and Oracle and DB2 and Oracle are fully supported on an NFS volume from those implementations.
Oracles list of vendors is here and IBM just supports Network Appliance as far as I know but if it works with Oracle then it's going to work with DB2 and WebSphere. It's a test statement rather than a functional problem (although this isn't always the case).
Basically, if a database vendor says it's ok to host a database on a mounted NFS volume then they are telling you the writes are safe on that NFS implementation when configured correctly. You'll need to contact your NFS vendor to determine the exact settings to use.
If your vendor isn't on the lists above then call them and ask them how to guarantee sync writes only return when the data is written to the disk.
In addition to databases I think this would also apply to WAS transaction logs and if I remember correctly we even list SMB in addition to NFSv4.
Posted by: Gerhard Poul | February 13, 2006 at 12:38 PM