From Oracle FAQ
LGWR (LoG WRiter) is an Oracle background process created when you start a database instance. The LGWR writes the redo log buffers to the on-line redo log files. If the on-line redo log files are mirrored, all the members of the group will be written out simultaneously.
The following Unix/Linux command is used to check if the LGWR process is running:
$ ps -ef | grep lgwr oracle 31144 1 0 11:10 ? 00:00:00 ora_lgwr_orcl
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