[PLUG] Confusion about scsi standards...

[Michael Robinson]

I'm looking into why I'm getting IO errors with my scsi drives.  
Thinking it's a bad cable, I now wonder if I need a newer card
that is more recent on the LVD/se standards?  The drives are Compaq 
MODEL MA3043LP.  The label says Wide Ultra 2 scsi. 
Looking this up on google, I'm a bit surprised to run into the 29160 
adaptec controller.  It supposedly operates at 160,
twice the 2940U2W's 80 speed.  What happens if I plug a drive meant for 
ultra 2 wide 160 into an ultra 2 wide 80
controller?  Does the drive merely run slower?  These 68 pin LVD cables, 
what the difference between an Ultra 320
one versus an Ultra 160 one, etc.?  can I buy a cable for a newer scsi 
card that's 68 pin and use it on an older one?

It drops the same drive every time, probably a bad cable.  I wonder if a 
250 watt power supply for an onstream SC50 and four
of these compaq drives is too small?  I'm trying to get a new five 
position cable.  I'm almost tempted to get a box of 10 new
three position cables cheap and add a second scsi card.  Would I be 
better off with a different scsi card manufacturer?

I have tried swapping in my spare drive.  Unless the spare and the drive 
I swapped out are both faulty, I'm at a loss.
Why would it work for a while and then err out with an ext3 fs io 
error?   My coco had a  problem with a bad disk drive
cable which caused  behavior  similar to what I'm  running into.  Is 
there some site I can get a Linux friendly adaptec
2940u2w bios from, just in case it's a firmware issue?

/Is there something like memtest86 to test the scsi card itself?  I 
suppose if I still have trouble I can
assume the card is to blame, but I haven't ruled out undersized power 
supply.
/