On Tue, 2 Jan 2001, The Hermit Hacker wrote:
> > > > I can only imagine how they got databases working through NFS. Having
> > > > the backend on one server and the files on another is really quite risky.
> > >
> > > Well, both Microsoft and Oracle support NFS mounted database device
> > > files with NetApp filers.
> >
> > Quite a trick. NFS, being state-less, is really a bad platform for such
> > things. I know there is NFS locking, but even that is not 100%, if I
> > remember correctly.
>
> NFS is state-less if you use UDP connections ... most modern Unices
> support TCP NFS as well, providing you a stateful connection ...
A stateless procotol riding on a stateful protocol, is still stateless.
Think HTTP.
The fact that NFS is stateless or not, does not matter for database
application. In the supported configuration, only one server is allowed
to mount the database at one time anyway. The only issue is making sure
that NFS writes actually get written when the NFS servers says they have
been written to ensure database consistancy. Many NFS implementations ack
NFS writes before they are written NetApp uses a battery backed RAM as a
write cache.
Tom