script to rysnc to spare hard drive

[Gary Peltola]

> What about software RAID 1 (mirroring)? If the backup is not on another
> physical machine, seems like mirroring might be as easy as rsync, w/o
> any scary scripted rm -rf'ing or --delete. Plus, it's always up-to-date
> (at least between disk sync intervals, someone else can remind me what
> those are under ext2fs, ~30 sec, IIRC), whereas a scripted rsync would
> only be good up to the last go-round on the cron job, nightly in your
> example.
>
> Don't get me wrong, I love rsync, but seems like not quite the right
> tool for this job, IMHO.
>

We already got RAID 1, and honestly its worthless with file system errors / corruptions since it will in fact mirror errors and all.
The only true way to have a reliable backup of your file system is an exact mirror