Here is the daily/weekly cronjob I put together over the years to perform MythTV-related maintenance tasks on my backend server.

Before I do anything with the MythTV database, I ensure that it's not corrupted:

4 1,13 * * *  mythtv  /usr/bin/mysqlcheck -p --silent --extended mythconverg

Then I start the actual maintenance tasks. The first part performs a database backup:

5 1,13 * * *  mythtv  /usr/share/mythtv/mythconverg_backup.pl

which I previously configured by putting the following in /home/mythtv/.mythtv/backuprc:

DBBackupDirectory=/var/backups/mythtv
rotate=15

and creating a new directory for it:

mkdir /var/backups/mythtv
chown mythtv:mythtv /var/backups/mythtv

The second part of /etc/cron.d/mythtv-maintenance runs a contrib script to optimize the database tables:

10 1 * * *  mythtv  /usr/bin/chronic /usr/share/doc/mythtv/examples/maintenance/optimize_mythdb.pl

once a day. It requires the libmythtv-perl and libxml-simple-perl packages to be installed on Debian-based systems.

It is quickly followed by a check of the recordings and automatic repair of the seektable (when possible):

20 1 * * *  mythtv  /usr/bin/chronic /usr/bin/mythutil --checkrecordings --fixseektable

Next, I force a scan of the music and video databases to pick up anything new that may have been added externally via NFS mounts:

30 1 * * *  mythtv  /usr/bin/mythutil --quiet --scanvideos
31 1 * * *  mythtv  /usr/bin/mythutil --quiet --scanmusic

Finally, I defragment the XFS partition for two hours every day except Friday:

45 1 * * 1-4,6-7  root  /usr/sbin/xfs_fsr

and resync the RAID-1 arrays once a week to ensure that they stay consistent and error-free:

15 3 * * 2  root  /usr/local/sbin/raid_parity_check md0
15 3 * * 4  root  /usr/local/sbin/raid_parity_check md2

using a trivial script.

In addition to that cronjob, I also have smartmontools run daily short and weekly long SMART tests via this blurb in /etc/smartd.conf:

/dev/sda -a -d ata -o on -S on -s (S/../.././04|L/../../6/05)
/dev/sdb -a -d ata -o on -S on -s (S/../.././04|L/../../6/05)

If there are any other automated maintenance tasks you do on your MythTV server, please leave a comment!