determine lun size

[Bill Hassell]

> locating alternate links...

The easiest way is to list the devices with the same TD numbers (CTD = controller or I/O card, T=target, D=disk) so if you're looking for alternate links for c12t2d4, do this:

ll /dev/dsk/c*t2d4

Then if you run pvcreate on one of the links, you can verify that it is the same disk with dd and xd:

dd if=/dev/rdsk/c12t2d4 bs=1k skip=9 count=1 2>/dev/null | xd -x

0000000 4c56 4d52 4543 3031 69ea 86f7 4b60 5af7
0000010 69ea 86f7 4b60 5c4a 0445 dcc8 0000 0006

The last two numbers (4b60 5af7) is the VGID (unique among every VG), and the 4th and 5th numbers on line 0000010 (4b60 5c4a) is the unique LUN or PV identification. Only alternate links will have the same exact PVID.

[Bill Hassell]

> dd if=/dev/rdsk/c12t2d4 bs=1k skip=9 count=1 2>/dev/null | xd -x

Oops, that should be: skip=8:

dd if=/dev/rdsk/c12t2d4 bs=1k skip=8 count=1 2>/dev/null | xd -x

That pesky keyboard put the 9 too close to the 8.

[Uday_S_Ankolekar]

If you have Hitachi arrays then probably you will have HDLM(Hitachi Dynamic Link Manager) installed on servers. It's load balancing software from Hitachi.
you can run dlnkmgr commands to see lun details and alt paths etc. It's useful utility to have if you are dealing with Hitachi Storage disks.

USA..