Date: Wed, 15 Nov 2000 23:05:38 -0500 (EST) From: Mikhail Teterin <mi@aldan.algebra.com> To: scsi@freebsd.org Subject: same drives acting differently Message-ID: <200011160405.eAG45gq05238@aldan.algebra.com>
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I have a pair of seemingly identical old drives, which I wanted to turn into a small raid array using ccd: da1 at sym1 bus 0 target 0 lun 0 da1: <SEAGATE ST32550N 0021> Fixed Direct Access SCSI-2 device da1: 10.000MB/s transfers (10.000MHz, offset 15), Tagged Queueing Enabled da1: 2047MB (4194058 512 byte sectors: 255H 63S/T 261C) da2 at sym1 bus 0 target 1 lun 0 da2: <SEAGATE ST32550N 0022> Fixed Direct Access SCSI-2 device da2: 10.000MB/s transfers (10.000MHz, offset 15), Tagged Queueing Enabled da2: 2047MB (4194058 512 byte sectors: 255H 63S/T 261C) As I was trying to figure out the best interleave factor, I noticed, that systat reported different figures for the drives as the rawio benchmark was running. Something like this: Disks ccd0 da0 da1 da2 da3 acd0 cd0 KB/t 16.00 0.00 2.00 1.60 0.00 0.00 0.00 tps 78 0 314 392 0 0 0 MB/s 1.21 0.00 0.61 0.61 0.00 0.00 0.00 % busy 97 0 34 97 0 0 0 See, the same amount of MB/s, but seriously different busy percentage. This is quite consistent for reading and writing parts of the rawio -- the da1 is always less busy than da2. I'm wondering if the da2 is dying on me, or what else is wrong with it, or is this because it is the second on the same SCSI chain, or what... Any ideas? Thanks! -mi To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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