The 'truncate log' command from within sp_ctrl can be used to truncate (remove all data from) the event Log in the log sub-directory in the Shareplex variable-data directory. These logs accumulate data and eventually can consume a large amount of disk space. The truncate log command allows you to truncate the logs after the data has outlived its usefulness. This command does not affect replication. You can issue it while replication is active and data is in the queues.
If you want to move out the trace log manually then you will need to stop Shareplex and move out the trace log and restart Shareplex.
You can also set the parameter SP_SLG_LOG_MAXSIZE to appropriate log size (for both event log and trace log) in MB.
This parameter controls the size of the Shareplex Event and Trace logs. You can set it based on the amount of available disk space to ensure that the logs do not consume too much space. Before writing to a log, Shareplex checks the log's size. If the size is larger than the value of this parameter, Shareplex truncates that log before writing to it.
NOTE: default log size is 500 MB
Range of Valid Values: 1 to 2048 in increments of 1 MB.
Takes effect: when Shareplex is restarted.
It is important to note that both event log and trace log size are effected by this parameter.