LVM/MirrorDisk UX help

[l. ray herbig]

Here's my situation. I have a very old external array on a very old hp9000 B1000 hpux 10.20. The array contains two drives; one of the drives has failed. However I believe the drives were mirrored. The two drives in the array are in a volume group called vgarray. I tried to vgreduce the failed drive out but it complains about the vg not being active. I cannot activate the volume group with vgchange -a y vgarray; the system freezes and reboots; it does the same if I give it -q n.
Is there someway to change the volume group so that it no longer looks for the failed drive without crashing the system through vgchange.

The failed disk is c4t6d0 in the volume group vgarray.

Here is the volume group layout...
# strings /etc/lvmtab
/dev/vg00
/dev/dsk/c3t6d0
/dev/dsk/c3t5d0
/dev/vgarray
/dev/dsk/c4t5d0
/dev/dsk/c4t6d0

Drive c4t6d0 is missing from ioscan

# ioscan -fnC disk
Class I H/W Path Driver S/W State H/W Type Description
=======================================================================
disk 0 10/0/14/0.0.0 sdisk CLAIMED DEVICE TEAC CD-532E-B CDROM
/dev/dsk/c0t0d0 /dev/rdsk/c0t0d0

disk 1 10/0/15/1.5.0 sdisk CLAIMED DEVICE QUANTUM ATLAS10K-18LVD
/dev/dsk/c3t5d0 /dev/rdsk/c3t5d0

disk 2 10/0/15/1.6.0 sdisk CLAIMED DEVICE QUANTUM ATLAS10K-18LVD
/dev/dsk/c3t6d0 /dev/rdsk/c3t6d0

disk 3 10/4/3/0.5.0 sdisk CLAIMED DEVICE SEAGATE ST318275LC
/dev/dsk/c4t5d0 /dev/rdsk/c4t5d0


dd fails.
# dd if=/dev/dsk/c4t6d0 of=/dev/null bs=512 count=1
/dev/dsk/c4t6d0: No such device or address
dd: cannot open /dev/dsk/c4t6d0


Any help is greatly appreciated.


Thanks!

[James R. Ferguson · Accepted solution]

Hi:

You could try:

# mv /etc/lvmtab /etc/lvmtab.old
# vgscan -a -v
# vgchange -a y
# lvlnboot -R

Regards!

...JRF...

[Siju Vadakkan]

The following command will remove the disk which is marked as missing in the Vg but active in the /etc/lvmtab.

#vgreduce -l /dev/vgarray

[Bill Hassell]

> However I believe the drives were mirrored.

Normally, a failed drive will not cause any problems to the running system. Check to see that you have disk mirroring software installed:

swlist -l product | grep -ie mirror

If not, then the disk is not mirrored and you'll have to remove the entire volume group and re-create it, followed by a data restoration. Otherwise, I would check lvdisplay on one of the lvols on this disk just to verify that it is mirrored. To avoid errors caused by the bad drive, just pull it out. The system should boot and recover without any problem (if the disks are mirrored).

[piyush mathiya]

As your given note, i suggest to follow the below steps,

# mv /etc/lvmtab /etc/lvmtab.bkp
# vgscan -v
### If the volume group vgarry is still showing then. . .

# vgchange -a n /dev/vgarry
# vgexport -m /dev/vgarry.map vgarry
# mkdir /dev/vgarry
# mknod /dev/vgarry/group c 64 0x010000
# vgimport /dev/vgarry /dev/dsk/c4t5d0
# vgchange -a y /dev/vgarry
# mountall

It's going to work !!!


Regards,
Piyush Mathiya