Re: TIMEOUT ON CONTROL FILE ENQUEUE

Stan Brown wrote:
> Oracle version 7.3.4.5.0 on HP-UX 10.20 (yes I know it's ancient :-)
>
> Last night (perhaps during a hot backup, I'm not certain yet), our Oracle
> instance came to a halt. The trace file has this, and:
>
> ORA-00600: internal error code, arguments: [2103], [0], [0], [1], [900],
> [], [], []
> ORA-00447: fatal error in background process
> ORA-00600: internal error code, arguments: [2103], [0], [0], [1], [900],
> [], [], []
>
> In it. I managed to connect with svrmgrl, and do a "shutdown abort" Now,
> I'm working on getting a complete set of cold backups of the system as is.
>
> I've looked at the hardware, and I cannot find any problems with it. The
> hot backup, and a subsequent dump are sent to a remote machine which is
> mounted via NFS.I see errors in dmesg out NFS server timeouts, so I strongly
> suspect this is the root cause of the disaster.
>
> I've got several questions for the gurus here.
>
> 1. Besides a complete set of backups, is there anything else I should do to
> prepare for a recovery attempt?
>
> 2. What steps should I plan on taking for the recovery attempt?
>
> 3. Is their any _safe_ way to find out if any tablespaces were left in
> backup mode, prior to getting the backups? I ask this because it's likely
> to take 2 to 3 days to get the backups using the methodology I'm familiar
> with, and I really don't think this is the time to depend on an untested
> backup technique.
>
> I welcome any suggestions.
>
> Thanks.
>

It may be that a filesystem containing a controlfile has become not accessible. Maybe for safety reason a controlfile is placed on a different filesystem and that one has been unmount (for backup or something else) or communication with that storage area has been lost.

Before starting up the instance, I'd check where controlfiles are (initSID.ora file). Then I'd make a backup copy of each one and compare them to see if they is not a controlfile that is not up to date. Maybe the inaccessible controlfile has not been written to, causing the instance to hang. So you may receive an error message starting it up because that controlfile is not up to date. In this case you should copy one of the good controlfiles over the bad one, but it would be better to backup the whole instance before, just to be sure... ;-)

In this case you can easily return to the starting point.

Remember, if you can, backup before starting recovery too. If you make a mistake, you can start again...

Umberto Received on Tue Sep 13 2005 - 05:06:07 CDT