Thursday, April 06, 2006

Uncommon Oracle Startup Errors

An installation running Oracle 9iR2 databases in production had non-typical messages in the alert.log. The databases had been installed on a fresh OS install, so there were no upgrade issues. The databases had been running for over a year.

During startup, non-default parameters are listed in the alert log. There were several messages about deprecated mts_ parameters. The installation DBA had taken favorite Oracle 8i settings and dropped them into Oracle 9i. The DBA had English as a second language, and did not investigate the meaning of deprecate. The alert.log message did not include an "ORA-99999", so the DBA ignored the message.
Simply setting the values to zero did not remove the messages - the parameters needed to be removed from the spfile. From alert.log:
Deprecated system parameters with specified values:
End of deprecated system parameter listing

The next alert.log message was, "Oracle instance running on a system with low open file descriptor limit. Tune your system to increase this limit to avoid severe performance degradation."
This message did not include an "ORA-99999", so this message was also ignored. The solution for this issue was to increase the operating system file descriptors. In the case of HP-UX 11.11, query the OS kernel to check the open file limits:
$ /usr/sbin/kmtune |grep files
maxfiles 4000 - 4000
maxfiles_lim 4000 Y 4000

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