Date: Sun, 17 Aug 1997 20:02:04 -0700 (PDT) From: Tom Samplonius <tom@sdf.com> To: Curt Welch <curt@kcwc.com> Cc: scsi@freebsd.org Subject: Re: expected performance with DPT RAID-5... Message-ID: <Pine.BSF.3.95q.970817195747.28679B-100000@misery.sdf.com> In-Reply-To: <9708180218.AA19946@mail.kcwc.com>
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On Sun, 17 Aug 1997, Curt Welch 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? > > 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? "cd" to one of the RAID-5 file systems and do a "dd if=/dev/zero of=testfile bs=64k count=1000". That will create a file called "testfile" 64MB in length (64k x 1000), and tell you how long it took to write it. Then reboot (the only way I know of clearing the FreeBSD file cache, and the DPT cache), and do a "dd if=testfile bs=64k of=/dev/null" to read the file back. On the write test I get about 3500000 bps, and the write test about 9200000 bps. These results don't seem very good too me. > 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. > > Curt Tom
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