FC tape drives

[Bruno Cunha]

Hello, just a simple question, if I connect 18 FC STK 9940 drives to a SAN with a FC switch and a HP box how does HP-UX will see the drives ? With heighteen diferent LUN's in the same target ID or ... ?

Thanks
Best Regards,
Bruno Cunha

[David Navarro]

NO, you can not see more than 8 LUN's per SCSI ID, Probably you will see Target 0 with 8 LUN's, Target 1 with another 8 more and Target 2 with the last two LUN's.
I Have not test it, but I think this will be what you will see.

[Doug Rauenzahn · Accepted solution]

The host will see all of the drives at unique hardware paths. Each drive will have lun 0, but they will have a different bus because each drive will be preceded by a fcpdev node in the ioscan output. They will probably all have the same target number.

Be aware that the FC 9940 is not supported by the stape driver on any HPUX release.

[Bruno Cunha]

If all the drives appear in LUN 0, what is the maximum target number that I can get ?
I ask this because now we have the possibility to buy 64 or 128 port FC switch native, instead of several switch in cascade.

Thanks

[Doug Rauenzahn]

Actually, you won't be limited by the target. Assuming you will be using N-ports, You'll be limited by the port number and domain ID in the hardware path. For instance, take this hardware path to a fc device:

1/2/0/0.3.28.255.0.0.0

3 => domain ID which is a unique ID for the switch in fabric
28 => port ID (actually it is 28-16=12) 12 is the switch port

You would only have the address space allocated in the hardware path for ports (1 byte?) , and maybe expanded by multiple domains if the switch vendor splits the ports into multiple domain IDs. You would then be OK.

Again, I suggest checking to see what switches and tape device are supported on HPUX.