The active log can be mirrored so that the mirrored copy can be used if the active log files cannot be read. There can be only one active log mirror.
Creating a log mirror is a suggested option. If you increase the size of the active log, the log mirror size is increased automatically. Mirroring the log can affect performance because of the doubled I/O activity that is required to maintain the mirror. The additional space that the log mirror requires is another factor to consider when deciding whether to create a log mirror.
If the mirror log directory becomes full, the server issues error messages to the activity log and to the db2diag.log. Server activity continues.