Re: Sensible backup approach?

Howard's advice is all very good, but it overlooks one very important risk. There is always the risk that the entire RAID array can be destroyed by some event such as a fire. A computer malfunction could also cause data loss.

I protect against such risks by keeping a copy off site, in addition to regular backups. For practical reasons, I accept the potential loss of recent data and only update my offset backup every few weeks. During a time when I had more data changing (and it was more vital) I updated my offset backup weekly. YMMV.

Unless you have a lot of money to spend, an offset backup of terabytes of data is probably not practical. You need to decide what is absolutely essential and protect it the most.


Howard S Shubs wrote:
In article <mrdelurk-978BA0.23444118032006@xxxxxxxxxxxxxxxx>,
George <mrdelurk@xxxxxxxxx> wrote:


The disks contain various parts of my life... my present and past work (design, music, writing) and my library of media in every format.


Okay, so you have a high rate of change and very important data which is irreplacable. I'd do these things:

0) Figure out which things will not be changing and which are not accessed all the time and write them to some kind of off-line media like DVD-R. Then delete them from your disks to recover space if needed. To be safe, you might want to write multiple copies out, in case one gets lost or degrades. Optical media such as CD-R and DVD-R as currently implemented are NOT archival, though they're almost certainly better than magnetic media.

1) RAID those disks to prevent losing ANY data. You change a lot of stuff every day, and losing the stuff you did 5 minutes ago will slow you down. You can use RAID 1 (mirroring, faster), where you use two disks of the same type to make sure the loss of one of the disks won't hurt, or you can use RAID 5 (redundant striping) where you use a bunch (>2) of the same kind of disks to make a large volume wherein the loss of any one disk is not fatal. In either case, you keep a spare drive in the closet for when one fails. If you've got the money, you keep two in the closet in case one of your spares is found to have failed while in the closet.

2) Establish some kind of backup regimen to save stuff off-line against accidental deletion, corruption, or just to be able to revert.

I wrote something of a web page about this kind of thing a while back at <http://www.shubs.net/backup.html> in which I discuss both RAID-style backup and archival backup. It's not finished, but I doubt it ever will be.

.

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