On 21/01/2010 09:07, Ian Collins wrote:
Robert Milkowski wrote:
On 20/01/2010 19:20, Ian Collins wrote:
Julian Regel wrote:
>It is actually not that easy.
>
>Compare a cost of 2x x4540 with 1TB disks to equivalent solution
on LTO.
>
>Each x4540 could be configured as: 4x 11 disks in raidz-2 + 2x hot
spare
>+ 2x OS disks.
>The four raidz2 group form a single pool. This would provide well
over
>30TB of logical storage per each box.
>
>Now you rsync all the data from your clients to a dedicated
filesystem
>per client, then create a snapshot.
>All snapshots are replicated to a 2nd x4540 so even if you would
loose
>entire box/data for some reason you would still have a spare copy.
>
>Now compare it to a cost of a library, lto drives, tapes, software +
>licenses, support costs, ...
>
>See more details at
>http://milek.blogspot.com/2009/12/my-presentation-at-losug.html
I've just read your presentation Robert. Interesting stuff.
I've also just done a pen and paper exercise to see how much 30TB
of tape would cost as a comparison to your disk based solution.
Using list prices from Sun's website (and who pays list..?), an
SL48 with 2 x LTO3 drives would cost £14000. I couldn't see a price
on an LTO4 equipped SL48 despite the Sun website saying it's a
supported option. Each LTO3 has a native capacity of 300GB and the
SL48 can hold up to 48 tapes in the library (14.4TB native per
library). To match the 30TB in your solution, we'd need two
libraries totalling £28000.
You would also need 100 LTO3 tapes to provide 30TB of native
storage. I recently bought a pack of 20 tapes for £340, so five
packs would be £1700.
So you could provision a tape backup for just under £30000
(~$49000). In comparison, the cost of one X4540 with ~ 36TB usable
storage is UK list price £30900. I've not factored in backup
software since you could use an open source solution such as Amanda
or Bacula.
A more apples to apples comparison would be to compare the storage
only. Both removable drive and tape options require a server with
FC or SCSI ports, so that can be excluded from the comparison.
I think one should actually compare whole solutions - including
servers, fc infrastructure, tape drives, robots, software costs, rack
space, ...
Servers like x4540 are ideal for zfs+rsync backup solution - very
compact, good $/GB ratio, enough CPU power for its capacity, allow to
easily scale it horizontally, and it is not too small and not too
big. Then thanks to its compactness they are very easy to administer.
Until you try to pick one up and put it in a fire safe!
Then you backup to tape from x4540 whatever data you need.
In case of enterprise products you save on licensing here as you need a
one client license per x4540 but in fact can backup data from many
clients which are there.
:)
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