topic Re: LVM in Operating System - HP-UX

LVM

masthan_1 — Fri, 26 Feb 2010 09:46:07 GMT

what is the importance of /etc/lvmtab file and /etc/lvmrc.conf file? if at any point of time this get corrupted, what would be the impact? Can anyone explain this. Also if we lost these files, how can we recover to have normal LVM functionality?

Re: LVM

Kapil Jha — Fri, 26 Feb 2010 09:53:51 GMT

/etc/lvmtab file has the list of devices which are inside the a particular VG.
If you remove it you can recreate it with vgscan(1) command

lvmrc file is

"This file is sourced by /sbin/lvmrc. This file contains the flags
# AUTO_VG_ACTIVATE and RESYNC which are required by the script in /sbin/lvmrc"

Its to decide whether u want vg to be activated automatically and how u want VG to be synced

"PARALLEL" - resync all VGs at once.
"SERIAL" - resync VGs one at a time.

BR,
Kapil+

Re: LVM

masthan_1 — Fri, 26 Feb 2010 10:00:28 GMT

Thanks for the answer. i like to have some more explanation..

Re: LVM

Jupinder Bedi — Fri, 26 Feb 2010 10:12:08 GMT

read this thread for lvmtab

http://forums13.itrc.hp.com/service/forums/questionanswer.do?admit=109447627+1267178957600+28353475&threadId=1083220

and for lvmrc do cat /etc/lvmrc and read this file . you will understand the concept.

Re: LVM

Kapil Jha — Fri, 26 Feb 2010 10:19:28 GMT

Its always better to do some google for the concepts because there are so many things and they really can not fit in a reply ;)

BR,
Kapil+

Re: LVM

Matti_Kurkela — Fri, 26 Feb 2010 13:17:21 GMT

The "vgscan" command can re-create the /etc/lvmtab file if you've lost it. However, if you have rebooted the system after the file corruption, you may have to first boot the system into LVM maintenance mode to run vgscan.

Read "man vgscan" before using the vgscan command: depending on your situation, there may be some steps you must do after it. The steps are listed in the man page.

Losing the /etc/lvmrc (no .conf!) may prevent the system from activating any VGs other than vg00 (which is handled specially at boot time).

To fix it, boot the system to single user mode (or to LVM maintenance mode, if single user does not work), activate vg00 manually, remount the root filesystem as read/write, mount /usr, copy a factory default version of /etc/lvmrc from /usr/newconfig/etc/lvmrc, and re-add your local customizations if necessary.

MK