Date: Thu, 14 Oct 1999 16:35:44 +0100 (WEST) From: Joao Pagaime <jpsp@rccn.net> To: Tom <tom@sdf.com> Cc: scsi@freebsd.org Subject: Re: FreeBSD 3.2 / Slow SCSI Dell PowerEdge 4300 Message-ID: <Pine.BSF.4.10.9910141617130.15842-100000@atlas.rccn.net> In-Reply-To: <Pine.BSF.4.05.9910140622150.11329-100000@misery.sdf.com>
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Thanks for the response! Sorry if I read a little strange, but I'm no SCSI specialist. However Dell does refer in the manuals to the board where the disks plug into as "backplane". Probably this isn't the rigth nomenclature. I think the server has a RAID option - with a different "backplane" - that we didn't purchase. In all cases I'm stuck with that board, because the disks draw power from it - signaling/data and power in the same SCSI interface (I'm sure that has a simple name for that...) I'm not even sure if I can connect that "backplane" to a normal SCSI controller (like an SCSI Card 2940U2W) because the architecture seems very proprietary... The disk optimization is a 'must' then... From 2 MB/s to something close to 80 takes a great deal of optimization. Thanks, Joao Pagaime -- FCCN - Fundacao para a Computacao Cientifica Nacional - Tel: 351-1-8440100 On Thu, 14 Oct 1999, Tom wrote: > > On Thu, 14 Oct 1999, Joao Pagaime wrote: > > > Hi all > > > > I have a very slow Pentium III/450 with 512MB RAM > > because disks tranfers are slow. > > > > Simple tests show a transfer rate of +/- 2MB/sec, > > when a PC with IDE can do easily at least 4 times > > that value. > > > > I think the problem is with the "Common Access Method" > > in the backplane, because although the controllers are > > found with no problem : > > What backplane? > > > ahc0: <Adaptec aic7890/91 Ultra2 SCSI adapter> rev 0x00 int a irq 11 on > > pci2.4.0 > > ahc0: aic7890/91 Wide Channel A, SCSI Id=7, 16/255 SCBs > > ahc1: <Adaptec aic7860 SCSI adapter> rev 0x03 int a irq 11 on pci2.6.0 > > ahc1: aic7860 Single Channel A, SCSI Id=7, 3/255 SCBs > > > > The backplane is reported as having only 3.3 MB transfer rate : > > > > pass2 at ahc0 bus 0 target 6 lun 0 > > pass2: <DELL 1x6 U2W SCSI BP 5.12> Fixed Processor SCSI-2 device > > pass2: 3.300MB/s transfers > > That isn't a backplane. That looks like some kind of special SCSI > device on your chain. Perhaps it is a backplane status reporting device > of some sort. But it is not the backplane itself. > > > Did anyone experience the same problem ? > > Can someone help me ? > > Any hints ? > > Any configurarion at the CAM level ? - I configured the kernel > > to debug CAM but I can only reboot the machine in a few > > hours... > > > > Thanks, > > Joao Pagaime > > > > PS: the disks are also reporter correctly : > > > > da1 at ahc0 bus 0 target 1 lun 0 > > da1: <WDIGTL WDE9180 ULTRA2 1.20> Fixed Direct Access SCSI-2 device > > da1: 80.000MB/s transfers (40.000MHz, offset 31, 16bit) > > da1: 8687MB (17793001 512 byte sectors: 255H 63S/T 1107C) > > > > da0 at ahc0 bus 0 target 0 lun 0 > > da0: <WDIGTL WDE9180 ULTRA2 1.20> Fixed Direct Access SCSI-2 device > > da0: 80.000MB/s transfers (40.000MHz, offset 31, 16bit) > > da0: 8687MB (17793001 512 byte sectors: 255H 63S/T 1107C) > > These wouldn't be Western Digital Enterprise drives would they? > > They are very poor drives. There are some messages in the archives that > you need to disable some features on them in order to get the performance > up to a reasonable level. > > Also, make sure you have a spare. They have a tendency to die too. > Usually in the 6months to 1year range. > > > > And here are a few miserable tests : > > > > > > Sparc Entreprise 1000 - very old : > ... > > But they use some rather nice Seagate drives. As I recall. I belive > that Sun uses only Seagate in all their higher lines. > > > Tom > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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