Specifying the log staging directory

You configure the log staging directory to specify where log files on RS secondary servers are staged before being applied to the database.

About this task

You must specify a staging directory for log files sent from the primary server before enabling delayed application of log files. No default staging directory is defined. The server creates additional directories in the directory specified by LOG_STAGING_DIR named ifmxlog_##, where ## is the instance specified by SERVERNUM. The directories are used to store the logical logs and are also used during the recovery of the RS secondary server. The staged log files are automatically removed when they are no longer required. If the files within LOG_STAGING_DIR are lost, and the primary server has overwritten the logs, then the RS secondary server must be rebuilt.

You must ensure that the directory specified by LOG_STAGING_DIR exists and is secure. The directory must be owned by user informix, must belong to group informix, and must not have public read, write, or execute permission. If role separation is enabled, the directory specified by LOG_STAGING_DIR must be owned by the user or group that owns $INFORMIXDIR/etc. If the directory specified by LOG_STAGING_DIR is not secure, then the server cannot be initialized. The following message is written to the online message log if the directory is not secure: 
The log staging directory (directory_name) is not secure.
You must also ensure that the disk contains sufficient space to hold all of the logs from the primary server, and that the directory does not contain staged logs from previous instances that are no longer being used.

To see information about the data being sent to the log-staging directory set for a RS secondary server, run the onstat -g rss verbose command on the RS secondary server.

If the write to the staging file fails, the RS secondary server raises event alarm 40007.

See HCL OneDB™ Administrator's Reference for more information.

To set LOG_STAGING_DIR:

Procedure

  1. Ensure that the directory in which logs are to be stored exists and is secure.
  2. Edit the RS secondary server onconfig file.
  3. Specify the staging directory as follows: LOG_STAGING_DIR directory_name where directory_name is the name of the directory in which to store the logs.
  4. Restart the server.

Results

You can also set the LOG_STAGING_DIR configuration parameter without restarting the server by using the onmode -wf command; however, the delayed application of log files must not be active when the command is run.