Jamier101 - 11:23 pm on Sep 11, 2010 (gmt 0)
On my server I have two internal SATA drives, the first is partitioned and takes the operating system and primary copy of my work which is mount as work. I then formatted the second drive and mounted it as backup. Crontab then runs a backup script each night to ensure that I have a backup for everyday of the week therefore I have 7 days to realise a mistake.
In addition, I also have a LACIE USB hard-drive which acts as a removable copy which I can take off-site. The backup script e-mails me each morning to tell me if the backups were successful so that I can address any issues, the most common is that the LACIE has been powered down for one reason or another.
Although there is no way to remain 100% covered for everything I find the best policy is to change the drives in my server every 3 years or if any signs of bad sectors start appearing.