I am having trouble with one SCSI tape drive. No idea why. It worked
on a mac68k netbsd machine. I posted previously. I looked through the
archive and saw that I was not the first person to ever have SCSI
problems.  

The tape PowerMacinstosh 6500/300 has the classic Mac 25 pin SCSI. The
ZIP and CROM are also SCSI. The Tape drive is a Maynard that reports
itself as an EXABYTE. The 9GB Hard Disk was an OWC Special, which I
believe is really a SeaGATE.

The configuration where I had endless errors was:

CPU->25 to 50 -> 9GB external-> 50 to Centronics -> tapedrive -> terminator

I changed it to

CPU->25 to Centronics -> tapedrive -> Centronics to 50 -> 9GB -> terminator

Now I get the following message from dmesg.
mesh0: timeout state 3

I don't even know what 'timeout state 3' means.

What drives me craziest is that using amanda it can write the tape
labels without difficulty. It is only when it tries to write to the
tape that it produces an error. 

Please, if you know:

1. Tell me if there is a way to determine and correct the state of my
SCSI chain. It strikes me that the behavior is similar to other times
I've had termination problems, but as far as I can tell the SCSI bus
is correctly terminated. Would I have better luck if it were not?

2. Tell me if there is a problem with my device cofiguration; for
example a reset command I should send to the tape drive using the "mt"
program.

3. Is there is a good test for tape drives, using a tape with unimportant contents, and tar, or dd, or cpio, commands, that can help?

Should I just pack it in and forego any attempt to use the tape drive
as part of this set up.

-- 
Josh Kuperman
josh@ssimr.com
http://www.ssimr.com

sd0 at scsibus0 target 0 lun 0: <SEAGATE, SX910800N, 8514> SCSI2 0/direct fixed
de0: enabling 10baseT port
mesh0: timeout state 3
sd0: 8669 MB, 4926 cyl, 27 head, 133 sec, 512 bytes/sect x 17755614 sectors
cd0 at scsibus0 target 3 lun 0: <MATSHITA, CD-ROM CR-8024, 2.0e> SCSI2 5/cdrom removable
st0 at scsibus0 target 4 lun 0: <EXABYTE, EXB-8500-85Qanx0, 06X0> SCSI2 1/sequential removable
st0: drive empty
sd1 at scsibus0 target 5 lun 0: <IOMEGA, ZIP 100, E.08> SCSI2 0/direct removable
sd1: drive offline
boot device: wd0
root on wd0a dumps on wd0b
root file system type: ffs
de0: setting full duplex.
de0: enabling Full Duplex 100baseTX port
mesh0: timeout state 3
mesh0: timeout state 3
mesh0: timeout state 3