Lost file

[Don Quixote de la Mancha]

On Tue, Sep 27, 2011 at 1:52 PM, Bob Plantz <rgplantz at gmail.com> wrote:
> the value of a backup = the cost of replacing everything since the last
> backup
>
> I have relearned the true meaning of this equation many times in my life.
> :-[

I Got Religion about backup when I lost the third hard drive of my
career.  To were partial losses, but one was a total loss that sounded
like the recording head had gotten bent or something.  That drive was
not at all backed up; I still have it, and may someday pay (a lot!) to
have  a data recovery service open the can in a clean room so they can
recover the data for me.

These days I have a high-end Xeon workstation that runs Fedora.  It
has a RAID 5 with an AMCC 9690SA SATA/SAS RAID Host Bus Adapter in
SATA mode.  I have four one-terabyte drives for a total of ~ 2.5 GB of
usable filesystem space.

I have not yet automated all of my backup process.  It matters to me
to be able to find my backed up files years later, so my backups are
HIGHLY organized.

 I roll tarballs that are placed in a staging area on my RAID.  It's a
filesystem on a separate partition, so it's not likely to suffer if my
main filesystem gets corrupted, but will suffer if I lose two or more
drives simultaneously.  But it has the advantage of saving me one
extra trip to my bank's safe deposit box when I swap backup drives.

I then use rsync to copy the staging filesystem's new contents to one
of my two one-terabyte backup drives.  These are quality drives, both
of then Western Digital RAID Edition III drives, a lot fancier than
one would normally use for a backup, but I figure they are less likely
to fail.

 I mount them each in a Wiebetech FireWire/USB/eSATA enclosure
(http://www.wiebetech.com/).  The Wiebetech enclosures have soft
rubber shock mounts rather than screwing the drives in an inflexible
way to the cases.

Once a week or so I swap the external backup drive on my desk with the
one in the safe deposit box.

The use of the internal staging area means that I only need to make
one trip to the bank each time I swap drives.  If I did not have that
staging area I would have to backup directly to one of the external
drives, then I would bring the other drive home, update that drive
from the previous home drive, then take the previous home drive to the
bank, making two trips, and also making data loss a little bit more
likely.

If you have a fast net connection there are lots of online backup
services that can be accessed via NFS or Windows filesharing.
Although my drives and cases had a big up-front expense the amortized
cost is less than using the online services and wouldn't run into
trouble in the event or corporate bankrupcy.


-- 
Don Quixote de la Mancha
quixote at dulcineatech.com

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