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From: mh@roger.imsd.contel.com (Mike Hoegeman)
Newsgroups: comp.databases
Subject: Re: Ingres and NFS
Message-ID: <60081@wlbr.IMSD.CONTEL.COM>
Date: 31 Oct 90 01:24:02 GMT
References: <4691@spdcc.SPDCC.COM> <1990Oct30.151205.5406@oracle.com>
Sender: news@wlbr.IMSD.CONTEL.COM
Organization: Contel GSG, Westlake Village, CA
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 In article <1990Oct30.151205.5406@oracle.com> kbittner@oracle.UUCP (Kurt Bittner) writes:
 >In article <4691@spdcc.SPDCC.COM> dyer@ursa-major.spdcc.com (Steve Dyer) writes:
 >>I've heard that Ingres rel 6 "doesn't work" on NFS.  I'd like
 >>to get a better restatement or a refutation of the problem. 

does'nt work is way too vague, but see the stuff below...

 >I'm certainly not an expert on Ingres, but there is a general problem with NFS
 >that affects all DBMS's running under it: NFS is stateless. 

Yes, NFS is stateless, but what does this have to do with the statement below ??
 
 >This means that in
 >the event of a system or network crash, NFS doesn't know enough information 
 >about what was going on at the time of the crash to do anything like a
 >transaction recovery or rollback. 

umm... The database itself usually does transaction recovery and
rollbacks. NFS has nothing to do with it, NFS just reads and write disk
blocks basically.

 >As a result, a database running on NFS would
 >have a high likelihood of corruption in the event of a crash. 

This is a bogus statement.

I used to use oracle on a machine which had it's database files on a
another machine (which had extra disk space but no oracle software) via
an NFS hard mount. I *never* had any problem with it and the nfs server
used to go up and down all the time unexpectedly (the power in the
building was pretty bad). When the server goes belly up, oracle just
blocks until it the server comes back up. if the client w/ oracle got
rebooted is has the same recovery abilites as if it was'nt using an NFS
file system.

 >
 >In general, I wouldn't be real excited about someone using NFS for a database
 >application even if it is technically possible.  Most database vendors now
 >provide the ability to use client-server software to achieve distrubuted access
 >to data that go beyond NFS in their capabilities (at least as far as the
 >DBMS app is concerned).  This is not to say, however, that you can't run other
 >apps on the same machine using NFS, just don't use it for the DBMS.

Well, i would'nt heartily recommend using NFS for databases either. But
in the case of oracle and probably most other db's that don't use a raw
filesystem in the context is described above it's not terribly
dangerous either.

Actually a funny thing about my weird oracle/NFS setup was that it ran
*faster* than when i had the files locally oracle machine because of
biod (read ahead deamons). (i was doing mostly db reads).