I had asked about inexpensive options for a large (~100GB) disk system
for a 2100. It seems the best thing to do is to get an EISA three-port
SCSI controller (SWXCR-EB), the StorageWorks RAID software kit
(QB-2XHAA-SA), and a bunch of Seagate 9GB drives. Two respondents
reported using a similar configuration successfully. One one pleased
with the performance, the other was not. I estimate the price for this
configuration (including glue and the time to put it together) to be
under US$60,000, which is about 40% less than the least expensive
discounted quote I got from DEC/Pioneer.
Things to note:
o The Seagate drives have high cooling requirements. If you use them,
make sure there is plenty of airflow over the drives.
o There reportedly was a bad run of the Seagate disks, but the problems
have been worked out.
o The configuration is not a high performance one. The bottleneck is at
the SCSI controller, and maximum throughput will only be about 16MB per
second.
o With such a large number of drives, cabling consideration are an
issue. Each SCSI chain is limited to 6 meters.
o All other things being equal, fewer spindles means lower performance
since latency will increase with fewer heads to seek.
o One respondent reported getting only about 6.4GB of useful space out
of a 9GB drive using RAID 5 and AdvFS.
o The DEC WWW server is incredibly handy. Check out
http://www.service.digital.com/.
o DEC may have a next-generation KZPAA PCI SCSI controller in the works
that supports fast/wide/differential SCSI.
o There are several third-party suppliers that offer compatible RAID
systems with prices in the US$0.75 to US$1.40 per megabyte range. These
include: Dataram (DTM1000), Falcon (FRD1000-RM5), CORE, and lots of
others.
Thanks to all who responded:
Dave Cherkus <cherkus_at_UniMaster.COM>
Bill Hanlon <bill_at_bwh.harvard.edu>
Alan Rollow <alan_at_nabeth.cxo.dec.com>
Morten <morten.hanshaugen_at_usit.uio.no>
Peter Smith <smithp%wrksta15_at_cobe.com>
Keith Chiles <kchiles_at_hccsf.com>
Eugene Chu <chu_at_musp0.jpl.nasa.gov>
--David Gadbois
Received on Sat Feb 11 1995 - 20:01:29 NZDT