Disk Enclosures
Showing results for 
Search instead for 
Did you mean: 

Storage enclosure Model A3312A

Vaish Raj

Storage enclosure Model A3312A


I am trying to connect Storage enclosure Model A3312A to D-class server.

The Storage enclosure has two rows of disks.Initially it recognized disks on one side and after changes to connections it recognized disks on other side.

Now it doesn't recognize any of the disks.

Any idea on how to connect cables/terminator ?

Thanks in advance



P.S. This thread has been moved from General to Disk Array. - Hp Forum moderator

Brian M Rawlings
Honored Contributor

Re: Storage enclosure Model A3312A

Hi, this little chassis is very straightforward. It is often called a Jamaica, its development codename, or a HASS enclosure (High Availability Storage System).

Basically, it is two vertical 4-slot backpanels that sit next to each other in one enclosure. At the top and bottom of each 4-slot backpanel is a SCSI port, one for in, the other for out or for termination. It doesn't matter which is the in port (top or bottom), the other one in the same vertical group of four drives is the out/terminate port.

Each slot has a set of SCSI ID switches, so you can set any slot to any SCSI ID. Make sure that each ID on the SCSI bus is unique. This seems simple, until you connect the two sides together, forming one long SCSI bus through all 8 slots. Then, it is easy to forget to change all the SCSI IDs on the 2nd half to something unique from the 1st half.

There are normally two ways this chassis would be connected to a server (D-class, for instance): single bus or dual bus (HA mode).

In single bus, you have one SCSI adapter in the D-class server, with one HD68 HVD (formerly fast wide differential) cable to one of the ports on the HASS, say the top left port. To make it all one bus, the bottom left port would have a short SCSI cable that would connect to the top right port, connecting the two halves into one bus. Then a terminator would be placed on the bottom right port, terminating the SCSI bus at its end.

In dual bus, there would be two SCSI adapters in the host, two cables, one to each half of the HASS. If each cable were connected to, say, the two top ports, then there would be two terminators on the bottom two ports. There would be no connection between the two SCSI busses, so you could mirror drives from one side to the other with no single point of failure (other than the server itself.

Hope this is clear enough, docs for this thing are hard to find anymore.

Regards, --bmr

If you join the two
We must indeed all hang together, or, most assuredly, we shall all hang separately. (Benjamin Franklin)
Vaish Raj

Re: Storage enclosure Model A3312A

Thanks Brian. I will try this and get back to you in a day.