[CentOS] Freeing pv space for snapshots

[Paul]

On Fri, January 5, 2007 7:26 am, Paul wrote:
> On Thu, January 4, 2007 11:11 pm, Aleksandar Milivojevic wrote:
>> Robert Becker Cope wrote:
>>> "Paul" <unix at bikesn4x4s.com> wrote:
>>>
>>>> Thanks, and where can I find a version of ext2resize that will work
>>>
>>> You want "resize2fs". Note that I've never used it to shrink a
>>> filesystem,
>>> myself, only to grow one.
>>
>> I've used it, and it works correctly (and it is available in CentOS
>> 4.4).  It shrinks file system as it should.  The only things Paul should
>> be careful is to first shrink file system, than logical volume and to
>> correctly calculate file system size and by how many extents he can
>> shrink logical volume.  If he shrinks logical volume too much, he might
>> end up loosing data.  Running fsck in non-destructive mode (fsck -N)
>> and/or attempting to mount file system read-only after he shrinks
>> logical volume might be a good idea to test all is OK.
>
> Thanks all.  And can I use it when the system is online?  I would think
> that would be the only way I could do it, cause I can't get to the ext3 fs
> of the LV unless its online.

OK, guess I answered my own questions:

# resize2fs -p /dev/VolGroup00/LogVol00 30G
resize2fs 1.35 (28-Feb-2004)
/dev/VolGroup00/LogVol00 is mounted; can't resize a mounted filesystem!

But how do I mount it when booted up on CD when it's burried somewhere in
the LVM on hda2?