Yes. As soon as the log exceeds a given size, it will be archived. Logging is switched to a new file. For me, the built-in log rotation works good enough:
-rw-r----- 1 www-data www-data 6.1M Sep 14 03:30 owncloud.log
-rw-r----- 1 www-data www-data 11M Aug 28 15:30 owncloud.log.1
* Define the maximum log rotation file size
* Enables log rotation and limits the total size of the logfiles.
* The default is 0 or false which disables log rotation.
* Specify a size in bytes, for example 104857600
* (100 megabytes = 100 * 1024 * 1024 bytes).
* A new logfile is created with a new name when the old logfile reaches the defined limit.
* If a rotated log file is already present, it will be overwritten.
* If enabled, only the active log file and one rotated file are stored.
'log_rotate_size' => false,