Re: Which hardware for saving backups?
On Mon, Jun 11, 2007 at 12:25:49PM +0200, Mitja Podreka wrote:
> Ron Johnson wrote:
> >On 06/11/07 04:40, Mitja Podreka wrote:
> >>Douglas Allan Tutty wrote:
> >>>If you have a spare computer, backup to that. This could be your
> >>>workstation. Add a drive or two (for raid1 there). Have it on a
> >>>separate power supply/UPS/whatever.
> >>>
> >>You mean separate power supply for additional drive(s)? Is it to
> >>switch it off after backup is finished?
No, I mean that if you use a separate computer that it be plugged into a
separate circuit via a separate panel on a UPS separate from the
computer that you are backing up.
> >>>Then, external USB makes sense. Get three: one hot, one on-site cold,
> >>>one off-site cold for disaster. Have you found an external USB drive
> >>>that takes 270 GB or will you have multiple drives and use your backup
> >>>software for volume management?
> >>>
> >>I found an external USB drive with 320GB. I was thinking to buy one
> >>for beginning. But now I might buy more.
> >
> >Don't buy a "prepackaged" external drive!
> >
> >Buy the enclosure and drive separately. You'll save money and can
> >choose the optimum sized drive for your needs.
> >
For single drives, look at addonics Jupiter (for 2.5" laptop drives) or
Saturn (for 3.5" drives). The Jupiter has some shock-absorbing so that
the drive is supposed to withstand a 1 m drop. Useful for off-site
backup to a bank's safety deposit box.
If you don't need the off-site, they also make different enclosures with
various adapter cards. E.g. a 5-bay enclosure with its own power supply
and hardware raid controller that will look to your computer like one
big drive.
A neat thing about the addonics is that they will connect to SATA,
eSATA, USB, FireWire, or IDE just by changing the cable.
I haven't used them but when I'm ready for external (non-CD) backup
that's likely what I'll do.
> >If you are doing backups for many faculty, a multi-drive FireWire 800
> >enclosure filled with 750GB drives might be what you need, instead.
> I don't need a big solution, although it might be used also for other's
> faculty needs. I'm in charge just of one server since our IT guys have
> no idea of Linux.
> How much backup space do I need for 270 GB of disk space?
>
It depends on how compressable the backup is and what compression
algorithm you use. gzip is relatively fast and pretty good. Bzip2 is
far slower but compresses a bit more. You'd have to try both and
compare time-to-complete and size of archives produced.
As for the size of drive to buy, find the sweet spot. (Drive +
enclosure) / GB. My guess is that it will likely be cheapest at around
500 GB for a 3.5" drive and a bit smaller and more money for 2.5"
drives. The smaller physical size only matters if your storage space is
constrained. If you're going with a fixed multi-drive enclosure you'll
probably use 3.5".
Something to consider: The price of an external multi-drive enclosure
with cables would probably cost more than an old spare computer (PII?)
plus a decent PCI ethernet card. I did that with my 486 but with ISA it
only does 10-T ethernet.
Poke around the school. You may be surprised what old computers are
around that work perfectly for what you want.
Doug.
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