Date: Thu, 2 Jul 1998 09:34:52 -0700 (PDT) From: Tom <tom@sdf.com> To: wjw@IAEhv.nl Cc: scsi@FreeBSD.ORG Subject: Re: Using a DPT controller, pros and cons Message-ID: <Pine.BSF.3.95q.980702092915.3956A-100000@misery.sdf.com> In-Reply-To: <199807021148.NAA23248@surf.IAE.nl>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 2 Jul 1998, Willem Jan Withagen wrote: > The other issue: > I've done 3 'dd if=/dev/zero of=/mnt?/bar' in parallel on the What blocksize? > system. > > 2 go to the DPT RAID-1 and RAID-5 > 1 goes to a seperate MICROPOLIS on the onboard ahc0 contoller. > > Now the MICROPOLIS get a sustained write stream of something like 2.7 > Mb/sec. The two RAID's do not stream the data at all. There's seconds of > time where either of the disks doesn't take any data. Then one disk has, > like 5Mb/sec, and the other 0-4 blocks/sec. > (And this get worse if rebuild are on the way) Well, you are operating the DPT with only narrow drives at 5mhz, so that is going to hurt. Also, the DPT controller is optimized for random access, not sequentional access. If "dd" writing represents a typical function of your system, you should probably disable the write cache completely. > and in the logs I find things like: > dpt0 ERROR: Marking 246407 (Write (10) [6.1.18]) on c0b0t12u0 > as late after 17711004usec > dpt0 ERROR: Marking 246409 (Write (10) [6.1.18]) on c0b0t12u0 > as late after 17739244usec > dpt0: Salvaging Tx 246378 from the jaws of destruction (10000/18149777) > dpt0: Salvaging Tx 246380 from the jaws of destruction (10000/18205091) You've got some real problems with your hardware. You shouldn't see any such warnings. > --WjW > > -- > Internet Access Eindhoven BV., voice: +31-40-2 393 393, data: +31-40-2 606 606 > P.O. 928, 5600 AX Eindhoven, The Netherlands > Full Internet connectivity for only fl 12.95 a month. > Call now, and login as 'new'. Tom 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?Pine.BSF.3.95q.980702092915.3956A-100000>