On bootup, the machine recognises the SCSI drives & controller in their
proper locations, then output is as follows:
Begin: Mounting root file systems
Begin: Running /scripts/local-top
Done.
ALERT! /dev/sda2 does not exist. Dropping to a shell!
The BusyBox shell then starts & gives a prompt. 5-10 secs later this
output is generated:
SCSI device sda: 143374650 512-byte hdwr sectors (73408MB)
SCSI device sda: drive cache: write back
SCSI device sda: 143374650 512-byte hdwr sectors (73408MB)
SCSI device sda: drive cache: write back
sda: sda1 sda2 sda3 sda4 < sda5 >
then similar output for sdb.
Hitting return after this gives a BusyBox prompt; then typing exit exits
from the shell & boot continues without further issues. (although note
that if you didn't know this was possible, there is no indication that
this will succeed).
i.e. it looks as if there is an ordering/timing problem with the
recognition/pickup of the drives.
Drives are Seagate ST373207LW (both 73GB); controller is Adaptec AIC7902
Ultra320 SCSI adapter (driver is ACI79XX PCI-X SCSI HBA DRIVER, Rev
1.3.11).
I'd be happy to provide more information/logs etc.