Re: async i/o via nfs?

"Volker Hetzer" <volker.hetzer_at_ieee.org> wrote

> > Shudder. How on earth did you decide to locate one of your controlfile
> > copies on a nfs-mounted drive? Why not all of them?

> I've got three copies, one near the db files, one on another volume and one
> on another machine. So far it has worked perfectly.

I concur with Sybrand. It is IMO a very bad idea to have a control file on a NFS mount.

> What would you suggest for having a copy on another machine?

Local copy. Then pick from rdist, remote copy, ftp, etc. There are numerous utilities that can make that easy and painless.

I use rdist myself a lot. I have a whack of Unix sh scripts I used for db admin & maintenance and a bunch of machines (from HP-UX, Solaris to Linux) to look after. I use rdist to make sure that all the machines are kept up to date with the latest sh scripts (and TNSNAMES files and standard crons) from the "master" machine. It works great (except for some Linux issues wrt .rhosts).

> > Try it, and follow the results by means of truss
> Where does oracle advises this?

Cannot remember exactly where, but I do recall reading that NFS is basically a Bad Idea (tm) in one of the Oracle 7 manuals.

> I've just had a look and what I got was "RAC on Linux Best Practices"
> and it says Asynchronous I/O can be used on whatever and nfs too.

Async i/o for control file i/o on NFS is IMO meaningless. It adds no technical or performance benefits.

--
Billy