Dual SCSI Hard Drives

I just installed 2 identical SCSI Hard Drives in an old server I'm rehabbing, and I think I might have missed a step in the setup routine, because only one drive is recognised. With both drives connected, my system says one drive is ID 0, and the controller card os ID 7,  but the other drive is missing. If I unplug the ribbon cable from that drive, the other (formerly missing...) Drive appears as ID 0, but the first drive is now missing. What do I need to do to make them both recognised??? I guess this would be like the Master/Slave jumpers in IDE, but how do you arrange dual drives in SCSI? I'm not nearly as proficcient is SCSI as I am in IDE, but M/S doesn't seem to be a SCSI setting. What did I do wrong??

Tom  

hubbyatschoolAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Lee W, MVPTechnology and Business Process AdvisorCommented:
SCSI works by giving each device an unique ID.  You have BOTH hard drives with the SAME ID - this is a no-no.  Set up one drive to be ID 1.  Look at the drive for a block of jumpers, possibly numbered 0,1,2,4 and put the jumper on the set of pins for 1.  Consult your drive's manual or possibly the top of the drive for more information on jumper settings for the hard drives.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
hubbyatschoolAuthor Commented:
I KNOW they are the same ID, but I can't find any jumpers on either drive to change it, so apparently ID 0 is the default where no jumpers are installed.

These drives are 8-10 years old, so I don't have any paperwork for them, but I guess I'll search for something online (specs or a manual). I thought there should be jumpers somewhere, but I think IBM must have made them invisible !!!! Good ol' Big Blue!!!

I'll look the drives over some more, and get back to you if I'm still betwixt & bewildered........... THANKS!!!!!!!!
pgm554Commented:
What type of interface ?
SCA(80in),68 pin,or 50 pin?
Active Protection takes the fight to cryptojacking

While there were several headline-grabbing ransomware attacks during in 2017, another big threat started appearing at the same time that didn’t get the same coverage – illicit cryptomining.

Lee W, MVPTechnology and Business Process AdvisorCommented:
If they are SCA drives (no obvious power connector) then there are no jumpers - you'd need an SCA adapter with Jumpers OR an SCA backplane in your system.  Otherwise, look underneath the drive for a set of pins, usually quite small ones (not nearly the size of standard jumpers on an IDE hard drive or CDROM).
hubbyatschoolAuthor Commented:
They are not SCA... They are regular 68 pin SCSI, and I think I might have solveds the mystery.....

Apparently, the pins are on the lower front side of the drive, and have been clipped off!!!!!  All that's left is a little nubbin, but there are markings underneath for 0,1,2,4. It looks like someone went crazy with sidecutter pliers, so if I can't get jumpers to make good contact with the (1/32" long) remnants, I guess I can just use them in other units as single drives. Anyway, thanks for all your help, and the education in SCSI technology...
Lee W, MVPTechnology and Business Process AdvisorCommented:
No one clipped them.  Some are just very tiny - this is common for SCSI hard drives - you need tiny jumpers
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Storage

From novice to tech pro — start learning today.