Friday, February 03, 2006

Automatic Archiving Does Not Restart if Disk Space is Full

Compliments of Jeff Hunter,
Consider an Oracle database running in archive log mode with automatic archiving turned on. When the archive log destination disk space becomes full, the automatic archiving will stop. As per Oracle's documentation, this is the expected behaviour. At this point, a message should appear:
ORA-00257: archiver error. Connect internal only, until freed.
When all of the online redo logs are filled up, the database will be in a hung state.
If you attempt to manually archive the files, you may receive the following errors:
SVRMGR> archive log next
ORA-16014: log 1 sequence# 199 not archived, no available destinations
ORA-00312: online log 1 thread 1: '/u03/app/oradata/DBADB/redo_g01a.log'

SVRMGR> archive log all
ORA-16020: less destinations available than specified
The following is a list of the possible ways to fix this problem:
1. Use the command:
alter system archive log all to '/u07/app/oradata/DBADB/archive';
NOTE: You MUST specify a location ref - ora-16014
2. Shutdown and restart the database. It may be necessary to do a Shutdown abort.

3. Use the REOPEN attribute of the LOG_ARCHIVE_DEST_n init.ora parameter:
Or run the following comand:
alter system set LOG_ARCHIVE_DEST_n = 'reopen'
4. Use the commands:
5. alter system archive log stop;

alter system archive log start;

The error ORA-16014 is the real clue for this problem. Once the archive destination becomes full, the location also becomes invalid. Normally Oracle does not do a recheck to see if space has been made available.
Using the command
alter system archive log all to '/u07/app/oradata/DBADB/archive';
gives Oracle a valid location for the archive logs. Even after using this the archive log destination parameter is still invalid and automatic achive does not work. This solution is best for systems that do not archive regularly but cannot be shutdown. You can also use this to allow you to do a Shutdown immediate instead of Shutdown abort.

Shutdown and restart of the database resets the archive log destinstation parameter to be valid. Do not forget to make disk space available before starting the database.

Use the REOPEN attribute of the LOG_ARCHIVE_DEST_n parameter to determine whether and when ARCn attempts to re-archive to a failed destination following an error. REOPEN applies to all errors, not just OPEN errors. REOPEN=n sets the minimum number of seconds before ARCn should try to reopen a failed destination. The default value for n is 300 seconds. A value of 0 is the same as turning off the REOPEN option, in other words, ARCn will not attempt to archive after a failure. If you do not specify the REOPEN keyword, ARCn will never reopen a destination following an error.

No comments: