[bananas] Big SCSI disks for AIPS

[Alberto Accomazzi]

"T. Joseph W. Lazio" wrote:

> We are considering the purchase of SCSI disks with a capacity of 18 GB
> or more for our main AIPS machine.  We have seen various disks offered
> for less than $1000.  (The cost, in dollars/MB, seems far better than
> the RAID systems I've been quoted.)
>
> Has anybody already purchased such disks? or had any experience with
> disks this size to offer?

Joseph,

depending on which point of price/performance you want your drives to
be, I would suggest considering buying either a 36 or a 50GB drive.
I just ordered an external 4-drive enclosure with a 36GB Seagate
Cheetah drive in it (10K RPM) for $1,250.  Bare Cheetah drives can be
had for just over $1K each, and from what I hear the 50GB Seagate
Barracuda (7200 RPM) are in the same price range.  I chose the 10K
drive because it is going to be used on a server doing lots of disk
I/O, so we wanted to maximize performance.  I haven't gotten the drive
yet, but have been always quite happy with Seagate products.

Hardware RAID systems are of course more expensive, but not
necessarily prohibitive.  One family of systems that I've heard of
which apparently give decent performance at a reasonable price are
SCSI-to-IDE based solutions such as the ones offered by RaidKing
(www.raidking.com).  A quote for a free-standing RAID-5 box with 170GB
of usable storage on it was quoted at ~ $5K last september.

Software RAID solutions (which we have been using on our servers since
it was the only thing we could afford) are not so great since they
are not OS independent, require non-trivial software and system
administration, and put a strain on the host computer which needs to
keep all the bits consistent, therefore decreasing performance.


Hope this helps,


-- Alberto


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Alberto Accomazzi                 NASA Astrophysics Data System / SIMBAD USA
aaccomazzi at cfa.harvard.edu             Smithsonian Astrophysical Observatory
v/f: 617-495-7076/617-496-7577                60 Garden Street, Mail Stop 83
http://cfa-www.harvard.edu/~alberto                 Cambridge, MA 02138  USA
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