Andre Pang wrote:
> I hope you didn't mean me when you were talking about that 'someone' :)
Nope. It is just the usual trend - "it is so cheap to do this"/switch
theme/"hot swap is the way to go". Just keep an eye out. It happens so
many times in discussion.
>
> Here's the evidence. Prices from eyo.com.au:
>
> Seagate U6 40GB: $211.20
> Promise FastTrak Pro 100 (hot-swap IDE + RAID0/1): $489.50
> Promise SuperSwap chassis: $225.50
Does it work reliably? (general question) This idea of mirroring in a
hot swap where you rip one out[1] to act as the back up has to be
considered carefully. The biggest problem is how quickly does the new
drive get replicated and what performance hit does the workload take. It
is usually a tradeoff between instant replication and performance hit
(e-v-e-r-y t-h-i-n-g s-u-d-d-e-n-l-y s-l-o-w-s r-i-g-h-t d-o-w-n)
and remember that whilst it is replicating, you don't actually have any
reliability above single drive.
It is really horses for courses. Personally I still prefer tape at
$2,000 for the drive[3] and 12/24Gb DDS3 Dat for $20-$30 each, but I
would be saving for DDS4 now. If you are a company, then DAT devices are
getting better value and there is also Exabyte.
...snip...
> If you _don't_ want hot-swap, but still want IDE removable (where
> you have to turn off the computer to swap hard disks), you can get
> those drive bays at plenty of places, usually costing about $60 or
> so for the IDE interface, and $30 for each 'drive bay'.
Try NASA Tech for about half the above, atm, and they are advertising
them with fans.
>
> Another solution might be to look at the ORB removable drives.
> Each disk holds 2.2GB, and the drive costs $350, with each disk
> costing about $80.
Jon also mention Jazz, Zip or Peerless in addition to the Orb.
Three words why not; proprietary, speed and cost.
Proprietary [4]- as I find that I sometimes need to recover stuff 10
years+ later[2], I need something that will work with much different
hardware and many operating systems. Zip drives (100Mb) have been around
for about that long, but not by design of the manufacturer. So I'm loath
to recommend this sort of device to anyone for backup.
On the otherhand, if your total time frame is less than a year, they may
work for you.
Speed - they are not always that fast. Again, the usual trade off.
Cost - For a few people who only need one or two platters, perhaps they
are best. Nowaday, a CD burner is far more cost effective and far more
permanent.
These devices always lose out to tape when you start to consider a
genuine multi-generational backup system (GFS). The cost of platters
really add up and the platters do not store that much stuff..
Lastly, as far as a data swapping devices, they are expensive compared
to old hard disks and some cold swap draws.
This is all just my 2c. It really is a matter of what works for you, but
over the years, I've stuck to tape and found it a worthwhile investment
for serious backups. A CD burner fills the small job gap now instead of
multiple floppies.
[1] Hint - don't just rip one drive out. Signal the system to shut one
down.
[2] Updating text for new editions of books as just one example.
[3] tape is synonymous with SCSI tape drive in my meaning.
[4] I've found that most "proprietary" backup systems; Alexandria,
Arkeia, etc are actually using cpio, dump, etc with a index to the
multiple dumps as the first file on the tape. This means you can usually
recover backups with out the proprietary software. All you loose is the
stored indexes to what is on what tape.
--
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email: [EMAIL PROTECTED] www: http://www.woa.com.au
Wombat Outdoor Adventures <Bicycles, Books, Computers, GIS>
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