topic Re: Cabling for disk array in Operating System - HP-UX

Cabling for disk array

gene egournov_1 — Mon, 12 Feb 2001 18:18:25 GMT

Hello,
Currenly we have a HP12 Autoraid connected to a host computer via 1 SCSI controller on a core I/O. We are planning on installing two HP-PB cards to get an array off of the core I/0, and connect the array using 2 SCSI controllers, 2 SCSI Buses. I understand that after doing so a hardware paths to the LUNs would change. Could someone tell me if I need to make any LVM config changes to reflect the new hardware paths.

Thanks,
gene egournov

Re: Cabling for disk array

Denver Osborn — Mon, 12 Feb 2001 18:42:40 GMT

I'd suggest using vgexport and vgimport for your changes. Here's a quick rundown on one possible solution.

1)umount and deactivate the vg, then export it.
vgexport -v -s m /tmp/vg_name.map

2)make your HW changes and bring system up.

3)import your vg
# mkdir /dev/vg_name
# mknod /dev/vg_name/group c 64 0x??0000 <-minor number will be unique, check w/ ll /dev/*/group
# vgimport -v -s -m /tmp/vg_name.map /dev/vg_name

You could also search the forums for vgexport and vgimport

Hope this helps!
-denver

Re: Cabling for disk array

Byron Myers — Mon, 12 Feb 2001 22:30:36 GMT

Gene,
An additional task will be to add the pv-links into the volume groups since you will be adding a second path to the LUNs. For each new LUN on one controller to the autoraid run "pvdisplay /dev/dsk/. This will show you the "alternate link" for each LUN. add these "alernate links" into the vg's with vgextend.