Identify PV device in HP-UX 11.31

Lincoln Zuljewic Silva — Thu, 08 Sep 2011 18:44:30 +0000

In HP-UX 11.31, LVM doesn’t use “ctd’ (ie: /dev/rdsk/c2t1d0), but DSF to balance the throughput between many device paths., so if you need identify what physical device represent that logical device, you can use ioscan, for example:
server@root:/root # vgdisplay -v vg00 --- Volume groups --- VG Name                     /dev/vg00 VG Write Access             read/write VG Status                   available Max LV                      255 Cur LV                      12 Open LV                     12 Max PV                      16 Cur PV                      1 Act PV                      1 Max PE per PV               4385 VGDA                        2 PE Size (Mbytes)            16 Total PE                    4375 Alloc PE                    3998 Free PE                     377 Total PVG                   0 Total Spare PVs             0 Total Spare PVs in use      0 VG Version                  1.0 VG Max Size                 1122560m VG Max Extents              70160
--- Logical volumes --- LV Name                     /dev/vg00/lvol1 LV Status                   available/syncd LV Size (Mbytes)            2000 Current LE                  125 Allocated PE                125 Used PV                     1
LV Name                     /dev/vg00/lvol2 LV Status                   available/syncd LV Size (Mbytes)            16384 Current LE                  1024 Allocated PE                1024 Used PV                     1 (...)LV Name                     /dev/vg00/lvol12 LV Status                   available/syncd LV Size (Mbytes)            5120 Current LE                  320 Allocated PE                320 Used PV                     1 --- Physical volumes --- PV Name                     /dev/disk/disk4 PV Status                   available Total PE                    4375 Free PE                     377 Autoswitch                  On Proactive Polling           On

Note that the pv name is “disk4”, not c2t1d3.

With ioscan you can reverse map it:
server@root:/root # ioscan -m dsf Persistent DSF Legacy DSF(s) ======================================== /dev/rdisk/disk3 /dev/rdsk/c2t1d0 /dev/rdisk/disk4 /dev/rdsk/c2t0d0 /dev/rdisk/disk5 /dev/rdsk/c0t0d0

Now we know that the “disk4″ is the physical disk located in 12/0/1/1/0.0.0
root@brux0044:/root # ioscan -fnC disk Class I H/W Path Driver S/W State H/W Type Description ======================================================================== disk 1298 12/0/1/1/0.0.0 sdisk CLAIMED DEVICE HP 73.4GMAP3735NC /dev/dsk/c2t0d0 /dev/rdsk/c2t0d0

Updating partition table in Linux

Lincoln Zuljewic Silva — Mon, 15 Mar 2010 14:53:16 +0000

When you use the "fdisk" to handle the partitions of a disk, depending on the disc, the "fdisk" will bring the following message:

WARNING: Re-reading the partition table failed with error 22: Invalid argument. The kernel still uses the old table. The new table will be used at the next reboot. Syncing disks.

No, you do not have to restart the server for the changes are applied, simply use the following command (example):
kpartx -a /dev/sda

This will re-read the partition table on /dev/sda and create the mapping of the system partitions (/dev/sda1, /dev/sda2, etc).

System Adm » disk

Identify PV device in HP-UX 11.31

Updating partition table in Linux