Backups: In Praise of Paranoia
Recently I had a disk drive failure, but I didn’t lose any data at all. In part that’s because that disk was “mirrored” to another disk using “RAID 1” or “mirroring”. In mirroring, software or hardware keeps two identical copies of a disk up-to-date as you go about your work, if one goes, you can replace the failed disk and (within a few hours) you can rebuild the mirror. It’s a good technology,and it allows you to continue to work when failure happens. Even so, I moved quickly to replace the disk and restore the mirror, despite having additional backups. (more…)