vgcreate hanging, lvm now locked and unable to kill process

[Gary Betts]

Hi,

I am using an Itanium system and trying to create a new vg. The vgcreate command is now just hanging (have left over 24hrs to see if the process would abort but it hasn't).

From reading some other threads in the Forum this does appear to be a know problem on Itanium system.

The problem is that the lock file has been created and I am unable to use any other LVM commands (msg "Cannot lock "/etc/lvmconf//lvm_lock" still trying ...
" appears).

I have been unable to kill the process in any way. Probably because it is hanging on i/o.

The only option I have left is to reboot the server. The question is will this remove the lvm_lock and kill the process on shutdown.

Also looking at lvmtab file it does not contain the new vg and accosiated disk. Is this going to cause an issue ?

Any advice would be helpful.

Thanks.

[Gary Betts]

Sorry amandment to above:

Also looking at lvmtab file it DOES contain the new vg and accosiated disk. Is this going to cause an issue ?

[Eric Antunes]

Hi Gary,

Read this DOC to understand the message before going further:

http://www1.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000063200620

Best Regards,

Eric Antunes

[Eric Antunes]

Or this link for Europe:

http://www5.itrc.hp.com/service/cki/search.do?category=c0&mode=id&searchString=KBRC00002639&searchCrit=allwords&docType=Security&docType=Patch&docType=EngineerNotes&docType=BugReports&docType=Hardware&docType=ReferenceMaterials&docType=ThirdParty&search.x=24&search.y=12

[Luk Vandenbussche]

Hi,

The most easy way is rebooting your server to solve the problem. Check if there are no other vg or lv process are running before you reexecute it.

[Dietmar Konermann]

Gary,

look like you are hitting this known problem with 11.23:

( SR:8606326791 CR:JAGae89066 )
On some larger disks, the vgcreate(1M) command fails and
may lead to a hang. For example, on a 146GB disk:
$ mkdir /dev/vg01
$ mknod /dev/vg01/group c 64 0x010000
$pvcreate -f /dev/rdsk/c2t0d0
Physical volume "/dev/rdsk/c2t0d0" has been
successfully created.
$ vgcreate vg01 /dev/dsk/c2t0d0
Increased the number of physical extents per
physical volume to 35003.
The process then hangs and cannot be killed. It may even
block a reboot. Manually adjusting the pe_size to 8MB will
workaround the problem.

This is fixed with PHKL_31500. At this point a reboot is the only way out. Later, you may use the -e option of vgcreate(1M) to workaround that issue (see above). However, I would urge you to install this LVM kernel patch asap.

Best regards..
Dietmar.

[Senthil Kumar .A_1]

Hi Gary,

This is a know problem in Itanium.

For Disks more than certain capacity (not sure exactly how much, approx 3 digit GB)..When u just simply give "vgcreate /dev/vgxx" it will hang as the Metadata structure can't be accomodated in 4MB LE/PE. As the vgcreate uses 4 MB by default. Try using higher number with "-s" option which determines the PE size.

ex : vgcreate -s 16 /dev/vgxx.

This is a temp solution, to get going with your vg creation. Usaully it souldn't take more than a few seconds as a thumb rule for this process.

As Dietmar Konermann suggested you can patch this issue..as you will never know, you might forget this point in future.. and may involke the command vgcrete without "-s" option.

regards.

[Venkatesan_5]

Hi Gary,

The same problem has been faced by me...what I did is rebooted the server...no other way...

after reboot i could find the newvg name in /etc/lvmtab and I exported the vg using vgexport /dev/vgxx.

then
# mkdir /dev/vg01
# mknod /dev/vg01/group c 64 0x010000
# pvcreate -f /dev/rdsk/c3t2d0
Physical volume "/dev/rdsk/c3t2d0" has been
successfully created.
# vgcreate -s 32 /dev/vg01 /dev/dsk/c3t2d0
the (-s) option will change the PE Size to 32 and now it will create the vg.
note: if you are adding another disk and extending the vg, no need to give -s option.
just give...
#vgextend /dev/vg01 /dev/dsk/c3t3d0.

hope this should solve your problem...eventhough try for installing the patch also...


regds,

Venkatesan.