ora_smon

[DIEGO_5]

Hi
When I tried to startup the db crash due ora_smon takes 100% cpu, what happened? the error is ora-00600

Thanks
Bye
Diego

[Fred Ruffet]

... You're probably facing a bug. ORA-00600 and ORA-07445 is usually a way Oracle tells you it doesn't know what happens.

You should have a look at your alert.log file to get more info. This can be found in the background_dump_dest directory (specified in init/spfile configuration file, available in $ORACLE_HOME/dbs). It may point you to log files in user_dump_dest.

What is your Oracle version ? It may be a good choice to go to a better patche version.

If traces are not explicit enough and you are in latest patchset version, you'll have to log a TAR in Oracle's Metalink.

Regards,

Fred

[Yogeeraj_1]

hi diego,

can you post more details about:
a. Version
b. Error message as indicated in the alert_.log

thanks
yogeeraj

[John Wimmer_1]

Some more things to consider:

1. after a restart on some oracle versions, the first thing SMON does is clean up the temp segments. If you TEMP tablespace(s) are improperly configured (i.e. extents are too small) then this can take a while.

2. Slow disks. We've had situations here before where the redo logs and control file were on slow disks and everything in the database was slow, including the TEMP rewrite as above.

I had that situation before, and it caused SMON to take 100%, but the database here just got slow, it didn't crash. May not apply here, but with what you've said, it sounds familiar.