Date: Wed, 20 Aug 1997 00:32:51 -0700 (PDT) From: Simon Shapiro <Shimon@i-Connect.Net> To: (Curt Welch) <curt@kcwc.com> Cc: scsi@FreeBSD.ORG, Tom Samplonius <tom@sdf.com> Subject: Re: expected performance with DPT RAID-5... Message-ID: <XFMail.970820003251.Shimon@i-Connect.Net> In-Reply-To: <9708180218.AA19946@mail.kcwc.com>
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Hi Curt Welch; On 18-Aug-97 you wrote: > Tom wrote: > > If I have 5 Barracuda 4LP 4GB drive (about 8MB/s raw > > read/write) on a single ultra wide channel on a DPT > > PM334/UW setup in a RAID-5 array, what kind of > > sequentional read/write performance should I expect? About 8-9MB/Sec on READ, 5-6 on write. Raid-5 is NOT optimal for sequential access and WRITE performance degrades with number of stripes. > Don't know what to expect, but I have a similar config. > > I have 5 Quantaum Atlas I 4G (fast wide) drives in a RAID-5 > config on one bus of of PM3334UW/2 and 5 Quantum Viking 4.55G > (ultra wide) also in a RAID-5 config on the other bus. The > system is a 180MHz Pentium Pro with 128MB of memory. The > DPT has a full 64MB of cache (non ecc). > > If you want me to run a test and tell you how it performs > I will. What type of test would you like to see? > > BTW, the system still crashes every few days. Don't know > for sure if it's probelms with the system, the DPT or the > DPT driver - I'm still working on it. It was very stable > before installing the DPT and the 10 new drives. Are you still having problems? What type? Simon
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