topic Pre HP-UX 11i v3 device special file creation in Operating System - HP-UX

Pre HP-UX 11i v3 device special file creation

hontoy — Sun, 09 Sep 2007 07:05:43 GMT

Hi Experts,
would you please advise on the following: In pre HP-UX 11i v3 a device special file has this syntax: /dev/(r)dsk/cCtTdD, with C: controller instance number, T: target id and D: LUN number.
With FC being introduced, T is not simply the target number anymore, it is subject to change in case of soft-addressing but also if it comes to explicit AL-PA setting.
Could someone please let me know how C is built? I.e. is there any algorithm that would allow me to calculate the "C" of a device that is going to be insf-ed?
Many thanks
kind regards

Re: Pre HP-UX 11i v3 device special file creation

Jdamian — Mon, 10 Sep 2007 06:49:23 GMT

The C value is given by the value of the instance in the ext_bus internal table:

ioscan -kfnC ext_bus

# ioscan -kfnC ext_bus
Class I H/W Path Driver S/W State H/W Type Description
==========================================================================
ext_bus 0 2/0/1/1/0/4/0 c720 CLAIMED INTERFACE SCSI C896 Ultra2 Wide LVD
ext_bus 1 2/0/1/1/0/4/1 c720 CLAIMED INTERFACE SCSI C896 Ultra2 Wide Single-Ended
ext_bus 8 2/0/4/1/0.127.140.19.0 fcd_vbus CLAIMED INTERFACE FCP Array Interface
ext_bus 9 2/0/4/1/0.127.140.255.1 fcd_vbus CLAIMED INTERFACE FCP Device Interface
ext_bus 10 2/0/6/1/0.123.140.19.0 fcd_vbus CLAIMED INTERFACE FCP Array Interface
ext_bus 11 2/0/6/1/0.123.140.255.1 fcd_vbus CLAIMED INTERFACE FCP Device Interface
ext_bus 2 2/0/8/1/0/4/0 c720 CLAIMED INTERFACE SCSI C896 Fast Wide LVD
ext_bus 3 2/0/8/1/0/4/1 c720 CLAIMED INTERFACE SCSI C896 Fast Wide LVD

In the output above, the CARD number of the disk device files (/dev/dsk/c8t* and /dev/dsk/c10t*) matches the instance number of the "FCP Array Interface" (8 and 10).

Pay attention that you MAY change those instance number by means of well-known ioinit procedure.

Each instance of an "FCP Array Interface" is able to handle a given number of LUNs (128 but I'm guessing).

When more than 128 LUNs must be handled, the FC driver creates a new instance (a new FCP Array Interface)

Re: Pre HP-UX 11i v3 device special file creation

hontoy — Mon, 10 Sep 2007 14:01:44 GMT

Thank you so much Oscar (o mejor: muchas gracias). Saludos hontoy