[linux-lvm] extending a logical volume

[Andreas Dilger]

On Jan 21, 2002  12:40 -0600, lembark at wrkhors.com wrote:
> The simplest way to handle it is unmounting, fsck-ing
> and re-mounting the thing immediately after your weekly
> backup, when users have to be off the system anyway
> [if you want to tell me that the system is too important
> to offline for a backup I'd strongly suggest finding a 
> 9-story window near the console, it'll be easier to 
> handle it yourself than have the users do it for you 
> after a crash looses all of the data].

I agree about the backups.  Most people don't think about
backups until it is too late.  I disagree about only doing
resizing at some late hour in the night though.  Many times
there are unexpected demands on storage, and the sysadmin
doesn't have control over the cause, but gets blamed for
the effect (i.e. running out of space).  Hence, online fs
resizing is a critical operation for an enterprise system.

> Even HP's LVM -- probably the most forgiving of all -- 
> has to be dismounted for extendfs; lvextend can be run
> any time you like.

???  That was only with the old HP LVM filesystem (UFS I think).  
If you formatted with the new filesystem (can't remember the name),
you could do online resizing.  AIX has had online resizing forever,
and so has XFS.  None of these allow even offline shrinking though,
which ext2/ext3 does.

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/