On Mon, 18 Nov 1996, Garrett D'Amore wrote:
>
> We don't use SSAs, but we do use ODS with RAID 5. Be warned however that ODS
> is slower than snail-snot when it comes to writes. A hardware RAID solution
> would be preferable, and we are pursuing hardware alternatives at our site.
>
I cannot fully agree: although we have not done any scientific timing tests,
the normal 'stress tests' that we ran showed that ODS RAID5 on our 4GB DEC
(Quantum? Seagate? whatever) disks is not any slower than our IBM 7137
RAID5, equally with 4GB disks.
A fair comparison is difficult: the IBM is 8 disks on 1 FW diff SCSI bus, the
Sun one 6 4GB disks on 3 (!) FW single-ended busses. I don't know in how far
the number of busses plays a role, nor can I remember how much write-back
cache the IBM RAID actually has. And I do not know what effect the available
memory (128 MB) on the SPARC 20 server has.
Anyway, this is with standard SCSI-attached disks on the Sun, not yet with
the StorageArray which has a write-back cache.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Rainer Toebbicke http://wwwcn1.cern.ch/~rtb -or- [EMAIL PROTECTED] O__
European Laboratory for Particle Physics(CERN) - Geneva, Switzerland > |
Phone: +41 22 767 8985 Fax: +41 22 767 7155 ( )\( )
