AutoMySQLBackup daily rotation only keep one day or latest backup day SOLVED

I had problems with my AutoMySQLBackup script on my ubuntu vps server, using the latest (3.0_rc6) available version of the script. The problem I had was that the daily rotation was not working as expected. The script kept yesterdays backup and did not remove it. It seemed to be happening randomly but nothing is ever random.

So today I took some of my precious time to investigate the problem. I found out that the problem was on line 803:

find "${CONFIG_backup_dir}/${subfolder}${subsubfolder}" -mtime +"${rotation}" -type f -exec rm {} \;

The rotation-parameter was configured to be "0". No problems with that as we only want to keep the latest backup file that was created today. But the mtime function with find is the problem where the argument to mtime are the number of whole days. While some backup-files wasn't created (or modified) a whole day from the current time.

-mtime n
       The primary shall evaluate as true if the file modification time subtracted from the initialization time, divided by 86400 (with any remainder discarded), is n.

So this is the problem. Now the solution can be fixed in various of ways. But I just needed a quick fix to this as I always want to only keep the latest mysql database backup files. So I modified that line (in particularly and some others just on case I need something else than 0 in rotation configuration) to:

find "${CONFIG_backup_dir}/${subfolder}${subsubfolder}" -mmin +$((60*23)) -type f -exec rm {} \;

As you can see from above, I'm looking for files that is 23 hours or older. So this covers my gap of backup file creation time.

I'm happy if this helps you out. AutoMySQLBackup is a great script but not really maintained the best.