At every 5 mins, just that one log would have been spit out 2304 times in 8 days, so yes, I could see it filling up quickly. Backup software logs are generated at certain instances, and are stored in the /db partition, however they require a special app to read them outside of the MCD. You can try to open them with any text editor, however the formatting will be off, you can however read the text portions, so you may be able to find some info.
The current log file is:
/db/database/files/pstswlog.db2
The backups are at:
/db/database/files/sw_log_backup
You *could* technically find these files and rename them to the original and then use ESM, however that's a last resort kinda thing. If you end up could to support, and the files are out of whack, I'm not sure what they would say/do, so make sure you have a snapshot of the logs.
I'd go back to those backup files and find the first instance of the log, then look at the logs prior to it.