Volume group shows a /dev/vg<name>/VGID Logical Volume... Does not show mounted... fuser shows opens

[Jack C. Mahaffey]

A perpelexing problem. I'm checking another HP-UX install and found a volume group named /dev/vg/VGID. It's a 4gb logical volume, it doesn't show up as mounted anywhere. I tried to mount it and it says it's already mounted. fuser /dev/vg/VGID shows a bunch of processes on the logical volume.

System does use Physical Volume Groups. We don't use raw devices. Any ideas where this came from and why it shows opened processes? Is it a byproduce us using Physical volume groups?

I was going to look into deleting the logical volume.


Thanks... jack...

[Clemens van Everdingen]

Hi,

If you do bdf you will see where it is mounted.

C.

[Jack C. Mahaffey]

bdf nor df nor swapinfo -mt show the logical volume.
jack...

[John Palmer]

Hi Jack,

No it won't be anything to do with PVG's.

Is it a link to another volume that shows up as mounted?

Do ll /dev/vg??/lv?? and check the link count (field 2).

Regards,
John

[Sebastian Galeski_1]

have a look at /etc/fstab and result of bdf command and
strings /etc/lvmtab
compare thats information
seba

[John Palmer · Accepted solution]

It could also be a device file with the same minor number.

Do an ll of /dev/vg and note it's minor number (0x??????). Each logical volume has a block and character device with the same minor number. If someone has created another device file with the same minor number then commands like lvdisplay and fuser will treat it and the 'proper' LV as the same thing.

Regards,
John

[Jack C. Mahaffey]

A duplicate minor number was the problem!!!

Thanks...

[John Palmer]

My guess is that VGID is the same minor number as lvopt01. ll /dev/vgopt will confirm this.

If so, you can just rm *VGID. Don't try to lvremove it.

Regards,
John

[Jack C. Mahaffey]

My vgexport map file contains an entry for VGID. Are there any implcations if I remove the entries in /dev/vgopt when the mapfile reflects the VGID entry?

Will creating another vgexport map file after the removal reflect the removal of the VGID entry?

jack...

[John Palmer]

No implications at all. Just remove the device files and either rerun vgexport or edit the map file.

The map file is ONLY used by vgimport to map the volume name to the minor number.

Regards,
John

[Helen French]

Hi Jack:

OK. here it goes:

1) The VGID which shows in the map file is a normal thing. When created with vgexport and -s option, then the map contains this *ID* so that, when you import it back with -s option, it will check all HDD with the same VGID and import it to the same VG. The *VGID* is specific and unique to each VG. All HDD in the same VG, has the same ID.

2) Now when you vgimport, if you don't use the -s option and if specify the HDD path seperately, then vgimport command will assume that *VGID* is also an LV ! and will import the same too. You can safely remove this file ( rm or rmsf ?)

HTH,
Shiju