Date: Thu, 14 Oct 1999 06:28:09 -0700 (PDT) From: Tom <tom@sdf.com> To: Joao Pagaime <jpsp@rccn.net> Cc: scsi@freebsd.org Subject: Re: FreeBSD 3.2 / Slow SCSI Dell PowerEdge 4300 Message-ID: <Pine.BSF.4.05.9910140622150.11329-100000@misery.sdf.com> In-Reply-To: <Pine.BSF.4.10.9910141552550.15842-100000@atlas.rccn.net>
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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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