[CentOS] CentOS Server Backup Options

Mon Mar 12 00:38:31 UTC 2012
Brian Mathis <brian.mathis+centos at betteradmin.com>

On Sun, Mar 11, 2012 at 8:12 PM, Scott Walker
<Scott_Walker at ramsystemscorp.com> wrote:
> What do you guys recommend for backing up a small CentOS server in a
> business environment.  It will have (3) 300gb drives in a raid 5 array but I
> don't anticipate more than about 25gb of data that needs to be backed up
> each night.
> I want a lot of backups with a rotation scheme that included daily, weekly,
> and monthly copies.  I want the daily copies of the data kept until the next
> week, and the weekly copy being kept for four weeks, and the monthly copies
> being kept for a year.
> The vendor is recommending a RD1000 Removable Disk device.  This looks like
> it has great specs.  Each cartridge holds 160gb (non-compressed) and the
> drive costs about $420 but seems that with each removable cartridge costing
> $128, we may be limited to how many cartridges we could have, thus perhaps
> not retaining backup instances as long as I like.
> I asked about a HP DAT160 tape drive.  Each tape holds 160gb
> (non-compressed) and the drive costs about $730, and each tape only costs
> about $24, so it would be economical to have lots of backup instances saved
> for a long period of time.
> I have been using tape and the backup rotation scheme mentioned above for
> over 20 years.  The vendor is telling me they don't recommend tape drives
> anymore and all of their customers are using removable hard drive for local
> backups.  Am I missing something?  My instincts tell me the tape drive is
> the right solution for a system with a small amount of data, where the
> system is used only from 8am - 5pm (so backup speed is not critical) and
> where we want to save backup instances for a long time before overwriting
> them.
> Any input would be welcomed.

The cost of disks is so low, it's very hard to justify tape.  Don't
forget you also need to have someone swapping the tapes every day or
week, or spend more for a robot.  For the amount you would spend on
those tapes, you can get many TBs of disk space.

In general it works very well to spend your money on disks and backup
to multiple locations.  With disk, you get so many benefits, such as
random-access recovery, and most disk-based systems support some level
of data deduplication.  If you use something like rsync backups with
hard links, there's also never a need for a full backup after the
first one.

I'm sure you will be able to come up with a few arguments against
using disk, and in some situations tape is better, but almost never
for some little server somewhere.  Once you start talking about
long-term archives and stuff like that, then yes, tapes are good.
Disks also need a different type of maintenance, such as running a
full read/refresh of the data every so often.  In the SAN world they
call this "scrubbing", though don't confuse it with the 'scrub'
command that securely wipes all data from the disk...

Some common disk-to-disk backup tools:
- BackupPC
- rdiff-backup
- dirvish
- Duplicity
- Duplicati

An overview of using rsync for backups:

❧ Brian Mathis