Howto get VolumeGroup information while a VG is not active

[William Wan_1]

Hi Guys,

For a system consistency check program, I need to gather VG information of all active and in-active VG/LV on regular base.

I know that to use vgdisplay and other LVM-commando's, the VG must be active whih the corresponding PV.
I tried vgcfgrestore -n vgxx -l, but it returns the name of the corresponding PV of that VG configuration file.

But I am wondering if anyone has some wonderfull idea for my problem.

Again, my situation is:

1: able to gather all VG/LV configuration on regular base ( information like strict mode, PE size, LV name, number of mirrors etc )

2: Not all VG are active. Some VG's can only be active once in a long while (maybe up to 3 months due to the application/package restriction)

Thanks for any kind of help / discussion in advance.

Regards,

William

[Rick Garland]

To get the LV names, you can go into the /dev/vg directory and list the contents. The LV names will be there.

Is the a MCSG config? If so, are the VGs active on another node? Do the vgdisplay there.

[Devender Khatana]

Hi,

It is not possible to find these informations about the VG's without activating them. The only thing you can find without activating will be the disks and LVOLs belonging to these VGs.

#strings /etc/lvmconf/vgxx.mapfile
&
#strings /etc/lvmconf/vgxx.conf can be used for this.

Also try SAM if it helps a bit here.

HTH,
Devender

[Gary L. Paveza, Jr.]

You can always attempt the vgdisplay, and if it fails, then try to do a vgchange -a r on the volume group (activate in read-only mode). If that succeeds, then vgdisplay it and then vgchange -a n it.

[G. Vrijhoeven]

Hi Willam,

If you are using MC/SG you can activate the volumegroup readonly do a vgcfgbackup and deactivate the vg again.

so
vgchange -a r /dev/vg?? && vgcfgbackup && vgdisplay -v vg?? && lvdisplay -v /dev/vg??/lvol? && vgchange -a n

HTH,

Gideon

[William Wan_1]

Thanks for all the help.

From the etc/lvmconf/vgxx.conf or /etc/lvmconf/vgxx.mapfile I can only retrieve information related to the PV.

I need to gather VG/LV information without activatating a VG at all.

I know that the VG information is store in the VG itself, without activating it, there is no way to discover them.

What I am wondering if there is anyother tools/application which keep the changes like vgcfgbackup/vgcfgrestore

unfortunataly, vgcfgbackup only store the information related to PV.

Regards,

William

[Geoff Wild]

As far as I know, there is no way to get the info you want without activating the vg.

What you will need to do, is perform regular vgdisplay -v's and save the info when those vg's are activated.

That said - you can activate a vg at anytime (as long as it isn't active on another host) - and you don't need to mount the file systems associated with it - so it won't harm your running application.

Rgds...Geoff