Backups

Just read about Journalspace on Slashdot.
Journalspace.com, a free blogging site, had some 14,000 bloggers.

Last week, they had a drive failure in their database server. They were using RAID 1 (drive mirroring) as their sole means of backup, meaning they had their server set so that anything written to one drive was mirrored to another; this theoretically allows you, in the event of a drive crash, to simply replace the bad drive and everything's fine because the data is mirrored.

Many ISPs do this and some tell their customers that it eliminates the need for individual backups.

Unfortunately, Journalspace just discovered that the problem wasn't that the drives failed, but that the data was overwritten and is completely unrecoverable. Someone or some thing caused all the data to be overwritten, and of course, since the drives were mirrored, the backup (mirror) was overwritten as well.
In other words, their entire business, and some 6 years worth of some 14,000 bloggers entries, are gone. They are simply giving up and closing down.

This should serve as a sobering reminder to double, triple, and quadruple check on your backup arrangements.