Date: Thu, 22 Apr 1999 18:41:37 -0400 (EDT) From: Mikhail Teterin <mi@misha.cisco.com> To: dnelson@emsphone.com (Dan Nelson) Cc: freebsd-scsi@freebsd.org Subject: Re: writing slower with SoftUpdates Message-ID: <199904222241.SAA96017@misha.cisco.com> In-Reply-To: <19990422172744.A51036@dan.emsphone.com> from Dan Nelson at "Apr 22, 1999 05:27:44 pm"
next in thread | previous in thread | raw e-mail | index | archive | help
Dan Nelson once wrote (regarding iozone reporting ~10% slower results with SoftUpdates, compared to without -- sync mount): > > WCE was ON on both drives: > > > > Checking SCSI drives for write-cache: > > <SEAGATE ST39102LW 0006> at scbus0 target 8 lun 0 (pass0,da0) > > <SEAGATE ST39102LW 0006> at scbus0 target 9 lun 0 (pass1,da1) > > I disabled WCE on both and re-ran the iozone tests. No noticable > > changes from the previous numbers... What really bothers me, is the > > fact that reading speed speed is consistently only 13-14Mb/s on one > > disk, while it is 17-18 (same as writing) on the other. Can it be, > > that one of the partitions I'm trying this on is /tmp (the other is > > /var/tmp)? There are no files in either one of them and they are of > > the same size and offset on two identical disks. > The different mountpoint shouldn't make any difference. I guess you > could dump the bad-block table for both drives, and see if your slower > disk has more relocated blocks than the faster one. "camcontrol > defects -u 0 -f block" will dump the blocklist. (pass0:ahc0:0:8:0): READ DEFECT DATA(10). CDB: 37 0 0 0 0 0 0 fd e8 0 (pass0:ahc0:0:8:0): RECOVERED ERROR asc:1c,0 (pass0:ahc0:0:8:0): Defect list not found field replaceable unit: 18 sks:ca,2 > If you still can't find the problem, try asking in the freebsd-scsi > mailinglist. CC-ed there. The machine is 350MHz PentumII with 128Mb of 100MHz RAM. The disks are LVD being the only targets on the LVD outlet of Adaptec 2940U2W. -mi To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199904222241.SAA96017>