Impact on playing with vg....

[Yan Berube_1]

I'm actually expecting some problem on one of my server, who is 9000/800/A500, running with hp-ux 11.00 and after a reboot my vg01 is not anymore available... as I have a lot of important data on it, don't want to do something wrong.

the problem I have is that vg01 is not activated. vgchange is giving me an error meg : Cross-device link... same if I do vgchange -a y -q n vg01... ioscan and ioscan told me that the disk is there and working. Don't really know what I can do now... Can you help me to not lost my data, plz ?

[Robert-Jan Goossens_1]

Hi,

Could be the /etc/lmvtab is corrupt ( one disk being recorded by two volume groups.

# strings /etc/lvmtab

If this is the case.

# mv /etc/lvmtab /etc/lvmtab.old

# vgscan -v

# vgchange -a y /dev/vg01

Hope this helps,
Robert-Jan

[saju_2]

Hi

Have you done a disk-disk copy before the reboot? I faced this error when the source disk and destination disk had the same VG info (VGID, PVID) etc.

Regards
CS

[Mel Burslan]

try to restore the LVM headers first

# vgcfgrestore -n /dev/vg01 /dev/rdsk/cXtXdX
(repeat as many times as necessary to cover all disks belonging to vg01)

If it still is reporting problems, try rebuilding the lvmtab

# mv /etc/lvmtab /etc/lvmtab.SAV
# vgscan -av

HTH

[Yan Berube_1]

Forget to tell that vg01 is in fact a VA 7110... So, when we do a vgcfgrestore are we doing it only once ?

[Devender Khatana]

Hi,

Can you post output of "strings /etc/lvmtab" and "ioscan -fnC disk" to know what are the device files before change and what is this now. If you have allready move lvmtab to some alternate location then use strings on that name only as the contents of old lvmtab will be helpful to know the path of old disks in the VG.

HTH,
Devender

[Yan Berube_1]

I did nothing until now... here is the result of few cmd line on the server:

# > strings /etc/lvmtab
/dev/vg00
/dev/dsk/c1t15d0
/dev/dsk/c3t15d0
/dev/vg01
/dev/dsk/c4t0d1
# > vgchange -a y /dev/vg01
vgchange: Warning: Couldn't attach to the volume group physical
volume "/dev/dsk/c4t0d1":
Cross-device link
vgchange: Warning: couldn't query physical volume "/dev/dsk/c4t0d1":
The specified path does not correspond to physical volume attached to
this volume group
vgchange: Warning: couldn't query all of the physical volumes.
vgchange: Couldn't activate volume group "/dev/vg01":
Quorum not present, or some physical volume(s) are missing.

# > vgscan -v
vgscan: Warning: couldn't query physical volume "/dev/dsk/c4t0d1":
The specified path does not correspond to physical volume attached to
this volume group
vgscan: Warning: couldn't query all of the physical volumes.
vgscan: The physical volume "/dev/dsk/c1t15d0" is already recorded in
the "/etc/lvmtab" file.
vgscan: The physical volume "/dev/dsk/c3t15d0" is already recorded in
the "/etc/lvmtab" file.
vgscan: The physical volume "/dev/dsk/c4t0d1" is already recorded in
the "/etc/lvmtab" file.
Couldn't stat physical volume "/dev/dsk/c0t2d0":
Invalid argument
Physical Volume "/dev/dsk/c4t0d0" contains no LVM information
Physical Volume "/dev/dsk/c6t0d0" contains no LVM information


/dev/vg00
/dev/dsk/c1t15d0
/dev/dsk/c3t15d0


Following Physical Volumes belong to one Volume Group.
Unable to match these Physical Volumes to a Volume Group.
Use the vgimport command to complete the process.
/dev/dsk/c4t0d1
/dev/dsk/c6t0d1

The Volume Group /dev/vg01 was not matched with any Physical Volumes.
Scan of Physical Volumes Complete.

[Devender Khatana]

Hi,

Could you also attach the output of "ioscan -fnC disk" to know what are the current device files for these disks. I assume that the device file for /dev/dsk/c4t0d1 has changed to /dev/dsk/c6t0d1 which is causing this. Or your disk in accessible from both paths.

Can you try
#vgexport /dev/vg01

To remove current config of the VG from the system & then try reimporting the VG from the new device file of the disk which is currently visible to system.

#mkdir /dev/vg01
#mknod /dev/vg01/group c 64 0x0?0000 (? should be unique identify by "ll /dev/*/group")
#vgimport /dev/vg01 /dev/dsk/c6t0d1

I assume some other changes at back end which is causing these device file changes. A reboot in any case can not cause this.

HTH,
Devender

[Yan Berube_1]

Here is the output of the ioscan -nfC disk:

Class I H/W Path Driver S/W State H/W Type Description
==================================================================================
disk 2 0/0/1/0.2.0 sdisk CLAIMED DEVICE HP DVD-ROM 305
/dev/dsk/c0t2d0 /dev/rdsk/c0t2d0
disk 0 0/0/1/1.15.0 sdisk CLAIMED DEVICE HP 36.4GMAS3367NC
/dev/dsk/c1t15d0 /dev/rdsk/c1t15d0
disk 1 0/0/2/1.15.0 sdisk CLAIMED DEVICE HP 36.4GMAS3367NC
/dev/dsk/c3t15d0 /dev/rdsk/c3t15d0
disk 3 0/4/0/0.8.0.108.0.0.0 sdisk CLAIMED DEVICE HP A6189B
/dev/dsk/c4t0d0 /dev/rdsk/c4t0d0
disk 5 0/4/0/0.8.0.108.0.0.1 sdisk CLAIMED DEVICE HP A6189B
/dev/dsk/c4t0d1 /dev/rdsk/c4t0d1
disk 4 0/6/2/0.8.0.110.0.0.0 sdisk CLAIMED DEVICE HP A6189B
/dev/dsk/c6t0d0 /dev/rdsk/c6t0d0
disk 6 0/6/2/0.8.0.110.0.0.1 sdisk CLAIMED DEVICE HP A6189B
/dev/dsk/c6t0d1 /dev/rdsk/c6t0d1


Please note that /dev/dsk/c4t0d1 is normally the primary path to access the Hp Virtual Array 7110 and the /dev/dsk/c6t0d1 is the alternate path... Can you confirm by doing the vgexport /dev/vg01, i will not lost any data ? Sorry, but don't want to lost something...

Many Thanks for your help

[Devender Khatana · Accepted solution]

Hi,

vgexport & import will not loose data.

Also please specify both the device files while importing the VG i.e.

#vgimport /dev/vg01 /dev/dsk/c4t0d1 /dev/dsk/c6t0d1

===================================
Physical Volume "/dev/dsk/c4t0d0" contains no LVM information
Physical Volume "/dev/dsk/c6t0d0" contains no LVM information


/dev/vg00
/dev/dsk/c1t15d0
/dev/dsk/c3t15d0


Following Physical Volumes belong to one Volume Group.
Unable to match these Physical Volumes to a Volume Group.
Use the vgimport command to complete the process.
/dev/dsk/c4t0d1
/dev/dsk/c6t0d1
=======================================

From you earlier post it seems /dev/dsk/c4t0d0 is the primary path & /dev/dsk/c6t0d0 is the alternate path to access VA, not /dev/dsk/c4t0d1 & /dev/dsk/c6t0d1 as posted by you. This is also confirmed by contents of your old lvmtab which states VG to reside on /dev/dsk/c4t0d1.

If you are right then your balance disks do not have any LVM information on them. Clarify this before proceeding further. Also find backend chnages done.

HTH,
Devender