Date: Thu, 8 Jun 2000 17:30:02 -0700 (PDT) From: Chris Wilkes <cwilkes@singingfish.com> To: freebsd-bugs@FreeBSD.org Subject: Re: misc/19129: AMI Raid Express 200 card extremely slow ( < 6MB/s) Message-ID: <200006090030.RAA42854@freefall.freebsd.org>
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The following reply was made to PR misc/19129; it has been noted by GNATS. From: Chris Wilkes <cwilkes@singingfish.com> To: "Aleksandr A. Babaylov" <babolo@zx.ru> Cc: freebsd-gnats-submit@FreeBSD.ORG Subject: Re: misc/19129: AMI Raid Express 200 card extremely slow ( < 6MB/s) Date: Thu, 8 Jun 2000 17:30:07 -0700 (PDT) On Fri, 9 Jun 2000, Aleksandr A. Babaylov wrote: > > File server with an AMI MegaRaid Express 200 card attached to a disk enclosure > > with 8 9G LVD SCSI2 drives, for a total of ~60G of RAID5 storage. > > Disk writes are extremely slow on it, around 6MB/s. Called AMI and they > > suggested moving from Linux to FreeBSD. Did that and I still see the same > > (bad) performance. > I see that if LVD controller works with non-LVD disks > I dont know AMI MegaRaid Express 200 card - are you shure it has > LVD interface? > I painfully know that the drives are LVD as I tried to hook them up to an Adaptec card when this was to be used with a Sun Sparc box. Didn't work as they do not support LVD drives. I've since started to use this array on my (then) Linux and now FreeBSD 4.0 one. Also the active terminator I have specifies "HVD" "LVD" and "SE" and the LVD light is lifted up. As for the card, it can support SE (single ended) or LVD (low voltage differential). I would imagine that if it were in SE mode my terminator would state that. I played around with the TCQ (command tag queuing) settings in the MegaRaid BIOS and that didn't seem to have an effect. Changing from raid 5 to 0 caused the times to be about cut in half. So instead of 6MB/s it would be closer to 10MB/s -- which is still half the speed of one of the internal SCSI drives! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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