[nycbug-talk] off site backup

[Jerry B. Altzman]

On 10/30/2005 1:53 PM, alex at pilosoft.com wrote:
> Disk drives fail in different ways. It is uncommon for drive not to spin 
> up after 1-2 years of shelf life - it is the *power on hours* that usually 
> kill you. Yes, there are certain failure modes that result in drive being 
> completely inaccessible - motor burning out, failing bearings, broken head 
> - but those are fixable (at about 1000$ cost) by a competent guy with a 
> donor drive, a soldering gun and a screwdriver. ;)

Given the engineering of drives, they *do* tend to like running all the 
time, or being off, but the torque to spin up from zero can be damaging. 
(So can dropping it.)

> Keep in mind that usually, with hard drives, it isn't hard to implement a 
> RAID system where failure of one drive doesn't impact your entire system - 
> much harder than tape, as you need >1 tape drive to make it happen.

Multi-tape-drive jukeboxes mitigate this nicely.

> Keep in mind that media for tape (say, ~40$ for LTO 200G) is about 1/4 of 
> cost of similar hard drive media.

with transfer rates correspondingly lower :-)

> So, its really apples and oranges. For historic (say, you have to do once 
> a week backup and store it offsite, with retention of 1 year) - it doesn't 
> make sense to do hard drives. For near-line and on-line, you want to use 
> hard drives.

Hard drives are the way to go if you have a time-to-recovery on the 
order of minutes instead of hours (or hours instead of days).

With recordable DVD media being relatively cheap, is anyone archiving to 
*that*?

> -alex

//jbaltz
-- 
jerry b. altzman  jbaltz at 3phasecomputing.com  +1 718 763 7405