resizing default redhat lvgroup. tips?

[Paul Johnson]

A tech at work made the default redhat install. I was stunned to
learn that RH client install does not create separate partitions for
everything anymore. There's one partition for the boot, and then a
single logical volume with everything else /.

The RH manual recommends to create /home in a separate volume, but
apparently the default does not do that. And I'd like to undo it.
But I'm not finding much discussion of this in the Internet.

I have been a conscientious objector on LVM for years. Old fashioned
partitions were good enough for my Dad, they have been good enough
for me! But maybe some of you have dropped your proud partition
tradition and have some ideas.

I don't even know all the right words to describe the "physical"
"logical" "volume" "partition" "group" "extents". So try to hear
"what I mean" rather than what I say.

There is one physical hard disk. The logical volume holding / is
almost empty. So I'd want to shrink that. Create a new place where
/home can go. And move it over there.

I gather I need to boot from the Rescue Disk and do the work from
there. But what do I do?

Here is the output of the commands I guess you might like.

# /sbin/fdisk /dev/sda

Command (m for help): p

Disk /dev/sda: 320.0 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 38913 312464250 8e Linux LVM

# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
298754424 10486964 272846840 4% /
/dev/sda1 101086 37000 58867 39% /boot
tmpfs 937696 0 937696 0% /dev/shm

# /sbin/pvscan
PV /dev/sda2 VG VolGroup00 lvm2 [297.97 GB / 0 free]
Total: 1 [297.97 GB] / in use: 1 [297.97 GB] / in no VG: 0 [0 ]

# mount
/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)

pj

--
Paul E. Johnson email: paul...@ku.edu
Professor, Political Science http://pj.freefaculty.org
1541 Lilac Lane, Rm 504
University of Kansas Office: (785) 864-9086
Lawrence, Kansas 66044-3177 FAX: (785) 864-5700

[David Hageman]

Paul,

This link has a howto on exactly what you want.

http://fedorasolved.org/Members/zcat/shrink-lvm-for-new-partition

I know you hear this alot, but it might be easier to just re-install. ;-)

--
========================================================
D. Hageman <dhag...@dracken.com>
Dracken Technology, Inc. http://www.dracken.com/
========================================================

[Jeffrey Watts]

Any reason you want to repartition?  Why don't you just shrink the logical volume and create another LV for /home within the VG?

resize2fs
lvresize
lvcreate
mke2fs -j
vi /etc/fstab
mount -a
profit!

And the reason that everyone uses LVM nowadays is because of situations exactly like this.  It also becomes especially handy when you want to add storage to an existing filesystem.

Jeffrey.

"He that would make his own liberty secure must guard even his enemy from oppression; for if he violates this duty he establishes a precedent that will reach to himself." -- Thomas Paine

[Russell Valentine]

Jeffrey Watts wrote:
> And the reason that everyone uses LVM nowadays is because of situations
> exactly like this. It also becomes especially handy when you want to add
> storage to an existing filesystem.
>
> Jeffrey.
>

I agree with Jeffrey, LVM is made for what your wanting to do, more so
than what was good enough for your Dad. It would be worthwhile to figure
it out and then you can start understanding the advantages.

I've used LVM on a house storage computer, it is really neat to be able
to add a drive and expand the size of the storage partition using that
drive or just parts of that drive with ease. It is very flexible, much
more so than various RAID striping configurations.

Russell Valentine