Date: Thu, 29 Apr 1999 12:14:52 GMT From: Marty Cawthon <mrc@ChipChat.com> To: flygt@sr.se, gunnar@pluto.sr.se Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Adding SCSI-disks results in failure Message-ID: <19990429121452A.mrc@ChipChat.com> In-Reply-To: Your message of "Thu, 29 Apr 1999 11:47:06 %2B0200" <19990429114706.C80160@sr.se> References: <19990429114706.C80160@sr.se>
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gunnar> We have a FreeBSD box that runs as new server. Yesterday we wanted to
gunnar> put in some more disk. We already have 7 disks attached to two Adaptec
gunnar> SCSI-controllers. 4 disks on one and 3 disks on the second. When we
gunnar> attach the 8'th disk to controller 2 we get a `device not configured`
gunnar> for the new disk.
gunnar>
gunnar> I suggested that we should upgrade the 2.2.7 to 3.1-RELEASE since the
gunnar> SCSI handling is better in 3.1. So we did and the box is working OK,
gunnar> except for the fact that we get the same error message.
gunnar>
gunnar> Anyone seen this behaviour?
Just last night I saw similar behaviour.
Three machines.
Hardware is identical.
3.1-Stable on 2 machines, 3.1-Release on a third
I had: Adaptec 2940UW controller (ID=7)
IBM Ultra wide SCSI disk drive (4 GB) (ID=12)
Panasonic SCSI CD-ROM (ID=0)
I added:
Yamaha CRW4416s SCSI CD-ROM R/W (ID=3)
All devices on a single 68 pin cable, with 68-50 pin adapters
for the narrow devices. Active termination at the end of the
cable.
One machine worked well.
Two other machines did not work well.
With the Yamaha CDR connected I saw "device not configured"
messages, and failed to "mount /cdrom".
(It is the Panasonic device, cd0, that responded this way).
Without the Yamaha CDR, the Panasonic (cd0) device worked fine.
The difference between the working machine and non-working machine
was the length and arrangement of the SCSI cable.
I have very good quality cables.
The spacing between SCSI connections is 9 inches.
I recall that I was told that the SCSI specification calls for
12 inches between devices.
I did not want "looped up cable galore" inside my machine
I had 9 inch spacing made on these cables.
The working machine had more than 9 inches spacing between
the Yamaha device and the Panasonic device. (Both SCSI-2 devices).
I had more connectors on the cables than I had SCSI devices,
so I re-arranged my cabling to have 18 inches either side of
the Yamaha device, and it worked fine on the second machine.
The third machine still exhibits troubles.
Maybe not cabling, or software, but possibly a bad drive (?)
However, the "device not configured" trouble was fixed by
adjustment of the cabling.
I suggest that you examine your SCSI cabling and measure the
cable spacing between devices.
Marty Cawthon
ChipChat
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