[Tfug] Backup program for Linux

[Zack Williams]

> RAID-1, a.k.a. mirroring.  THIS IS NOT A BACKUP, it's a way to keep running in
> the event of hardware failure of the primary drive.

The official term is an "availability" solution.

> However, if one drive gets corrupted, the other will mirror the corruption.  If
> the failure is in the disk controller, both mirrors can be useless.

Exactly.  This will get even worse as disks reach the point that
reading back the entire disk is close to the frequency of having an
uncorrected error, which will happen in the 2-4 TB size range for most
disks.  We'll need solutions like ZFS that do end-to-end checksums on
data, and can correct for errors.

> If you want a BACKUP, back up to a separate box, preferrably with versioning so
> you have multiple copies of each backed-up file.

Several good, automated ways of doing this:
 - rsync the files to another box
 - use a version control system like git/svn on your files
 - write them out to tape/CD/DVD, etc.

Or, all of the above.  Right now, I have windows, mac and other unix
machines rsyncing much of their data (much of which is in version
control) to one central box with some big disk , which writes them to
tape on a periodic basis.

Oh, and don't back up more than you have to - backing up those ISO's
of CentOS or Ubuntu you downloaded is probably not worth it as you can
get another identical copy anytime.  Backing up family photos, your
scanned tax documents, etc. is definitely worth it.

- Zack