[ILUG] SCSI disk not detected

[John N S Gill]

I'm trying to add a Seagate ST336704LW to a Redhat 6.1 system.

When the system boots it is unable to the detect the new disk.  It 
gets to the point when it tries to detect the disk and then keeps 
issuing messages like "aborting due to timeout" + tells me it is 
trying harder but never succeeds.  I'm assuming it is probing the 
disk for geometry information and isn't getting a response.

If i unplug this drive the system boots ok, below is an extract from 
the dmesg stuff showing the point it gets to before I run into 
problems.

scsi0 : Adaptec AHA274x/284x/294x (EISA/VLB/PCI-Fast SCSI) 5.1.20/3.2.4
       <Adaptec AIC-7890/1 Ultra2 SCSI host adapter>
scsi1 : Adaptec AHA274x/284x/294x (EISA/VLB/PCI-Fast SCSI) 5.1.20/3.2.4
       <Adaptec AIC-7880 Ultra SCSI host adapter>
scsi : 2 hosts.
(scsi0:0:0:0) Synchronous at 80.0 Mbyte/sec, offset 31.
  Vendor: QUANTUM   Model: ATLAS 10K 18WLS   Rev: UC81
  Type:   Direct-Access                      ANSI SCSI revision: 03
Detected scsi disk sda at scsi0, channel 0, id 0, lun 0
(scsi0:0:1:0) Synchronous at 80.0 Mbyte/sec, offset 31.
  Vendor: QUANTUM   Model: ATLAS 10K 18WLS   Rev: UC81
  Type:   Direct-Access                      ANSI SCSI revision: 03
Detected scsi disk sdb at scsi0, channel 0, id 1, lun 0

>>>> here is where the trouble starts <<<<

Any advice on what to try from here would be most welcome..

I've had a look through the SCSI-HOWTO but so far not had any 
inspiration.

John