We have extensively tested many scenarios of filer/server
failures in an Oracle environment. It is actually pretty
hard to lose any data and we have yet to find a way to
corrupt data if the steps outlined in the Technical
Whitepapers are followed. In particular, you MUST
use hard NFS mounts with Oracle. The situation described
below will only be a problem if soft NFS mounts are used.
Bruce Clarke
Network Appliance, Inc.
-----Original Message-----
From: Brian Tao [mailto:taob@risc.org]
Sent: Wednesday, May 24, 2000 9:43 PM
To: foo
Cc: toasters(a)mathworks.com
Subject: Re: Oracle and NTAP.
On Wed, 24 May 2000, foo wrote:
>
> Specifically they mentioned a situation they had experienced while
> testing a netapp/oracle environment which would cause total
> corruption and require restoration from backup. The specific
> situation is a case where the filer loses power but the DB server
> doesn't. Their claim is that if this occurs there is no method to
> recover the DB other than from backup.
Can they publish the exact steps they used to produce this
behaviour? We have various flavours of Oracle 7 and 8 (not 8i) with
tables stored over NFS on a clustered pair of F740's. We ran a simple
test that repeatedly inserted 100 rows, deleted 99 rows, inserted 100
rows, deleted 99 rows, ad infinitum. In the middle of that, we yanked
the power from one of the F740's. This triggered a failover to the
other F740. During that time, NFS service is suspended, and you can
see transactions from sqlplus hang for about 90 seconds. The NVRAM
logs are replayed during the takeover, NFS service is restored, and
the test script continues running. All records that we expect to see
in the database are accounted for.
Granted, this is a very simple test, so I'd like to know how your
DBA's were able to produce the behaviour they claimed to have seen.
--
Brian Tao (BT300, taob(a)risc.org)
"Though this be madness, yet there is method in't"