Three times in the last 2 months my server crashed (or locked up) during backups. I have my settings below. Any help to prevent this from happneing is appreciated.

Backup Status: enabled
Backup Interval: daily
Backup Retention: daily
Days to run backup: (all 7 days)
Remount/Unmount backup drive: disabled
Bail out if the backup drive cannot be mounted: disabled
Incremental backup: disabled
Backup Accounts: enabled
Backup Config Files: enabled
Sql Databases: per accounts and entire mysql database
Backup Raw Access Logs: disabled
Backup Type: standard
Ftp Backup Host (Remote Ftp Backup Only) = empty
Ftp Backup User (Remote Ftp Backup Only) = empty
Ftp Backup Pass (Remote Ftp Backup Only) = empty
Ftp Backup Directory/Path = empty
Use Passive mode for Ftp transfers: enabled

Pentium IV 2.4GHz
Enterprise 3.3
cPanel 9.9.9 R-10

Disk usage:
/dev/hda3 (primary) 11GB (17%)
/dev/hdc1 (backup) 17GB (24%)

I don't understand how the backup has more space used than primary. Anyone can explain this? Thanks.