what all can be done in LVM maintenance mode ?

[S. Singaravelu]

hello hp gurus !

Please help me to get answers for the following

1) What all LVM commands can be run in LVM maintenance mode?
2) What all LVM commands should not be run in LVM maintenance mode?
3) What are the limitations in LVM maintenance mode ?

Any pointers to complete details on LVM mode capabilities ?

thx
velu

[Michael Tully]

LVM maintenance mode basically means booting without LVM.

About the only thing you can do is Fix quorum - disk(s) that could be missing from volume groups.

LVM is not actually activated in LVM maintenance mode, so you have a limit on what you can do.

See comments in this posting and this document.

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x3e173d853cd9d5118ff40090279cd0f9,00.html

http://www.docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B2355-90762/B2355-90762_top.html&con=/hpux/onlinedocs/B2355-90762/00/00/62-con.html&toc=/hpux/onlinedocs/B2355-90762/00/00/62-toc.html&searchterms=LVM%7cmaintenance%7cmode&queryid=20030409-032027

[S. Singaravelu]

Further to my question !

I am aware of following (mentioned in HP rel notes and sys adm manual)

1) /stand/rootconf is required to get the system booted in LVM maintenance mode.

2) Don't get into multiuser mode frm LVM maintenance mode.

I heard the following from various sources in Internet:

1) LVM driver is not loaded.

2) LVM maintenance mode is to fix the LVM problems

Now my questions goes into specific

If LVM driver is not loaded in LVM maint. mode, how LVM maint. mode can be used to fix LVM problems such as runing lvlnboot, vgscan etc ?

Bit confused with this logic !! Any volunteer ?



thx
-velu

[Steve Steel]

Hi

lvm maintenance is just meant to kick start you

see man hpux
-lm Boot the system in LVM maintenance
mode, configure only the root volume,
and then initiate single user mode.

ALSO
http://204.92.69.141/cc/Content/OS/UNIX/HP-UX/HP-UX_LVM_mode.html

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xdd2fb941255cd71190080090279cd0f9,00.html

http://docs.hp.com/iknow/faqs/boot.html

http://archives.neohapsis.com/archives/hp/2002-q1/0090.html


Steve Steel

[Domenico_5]

you can modify information about lvm configuration like lvmextend and so on, but the system don't use lvm drive, infact if you run df you can see / mounted on /dev/root special file for read you disk

[Bill McNAMARA_1]

1> vgchange -a y vg00
in other words, only / and /stand are mounted. You typically boot into this mode when your lvm info is messed up and you can't boot into single user. ie PVRA and VGRA are messed up on the disk. lvlnboot to correct label file.

2> I would be very careful of doing vgscans in maintenance mode. especially when you're previously seeing errors relating to your /etc/lvmtab. The vgscan will recreate the lvmtab, from disk information, however, if the disks are corrupted it will create a 'corrupt' lvmtab. Also if you're a fan of dd'ing boot disks a vgscan can be dangerous if you do not lvlnboot correctly! recreating your fstab and forgetting to correct it on normal boot can be a common error.

3> it is a maintenance mode. / is not mounted on a standard1 lvm device file

man lvm!
man isl
man hpux
man vgchange

Later,
Bill