CentOS - Apr 2013 - Don't understand how to re-partition this setup or why it was made like this

Hello,

I did df -h on my CentOS 6.4 machine.

$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_ysg-lv_root
                       47G  8.8G   36G  20% /
tmpfs                 948M  372K  947M   1% /dev/shm
/dev/sda1             485M   62M  398M  14% /boot
/dev/mapper/vg_ysg-lv_home
                      4.6G  2.7G  1.7G  63% /home

What I don't understand is why is /home so tiny and how can I re-partition
this without having to nuke and rebuild my machine?

On 04/01/2013 09:00 PM, Yves S. Garret wrote:
> Hello,
> 
> I did df -h on my CentOS 6.4 machine.
> 
> $ df -h Filesystem            Size  Used Avail Use% Mounted on 
> /dev/mapper/vg_ysg-lv_root 47G  8.8G   36G  20% / tmpfs
> 948M  372K  947M   1% /dev/shm /dev/sda1             485M   62M  398M
> 14% /boot /dev/mapper/vg_ysg-lv_home 4.6G  2.7G  1.7G  63% /home
> 
> What I don't understand is why is /home so tiny and how can I
> re-partition this without having to nuke and rebuild my machine?
You'd have to resize the logical volumes your FS lives on (here:
vg_ysg-lv_root and vg_ysg-lv_home) and resize the FS as well.

Can be done booting off a rescue medium w/o any problems. Make sure you
do have a complete backup, though.

HTH,

Timo

On 2013-04-01, Yves S. Garret <yoursurrogategod at gmail.com>
wrote:
>
> $ df -h
> Filesystem            Size  Used Avail Use% Mounted on
> /dev/mapper/vg_ysg-lv_root
>                        47G  8.8G   36G  20% /
> tmpfs                 948M  372K  947M   1% /dev/shm
> /dev/sda1             485M   62M  398M  14% /boot
> /dev/mapper/vg_ysg-lv_home
>                       4.6G  2.7G  1.7G  63% /home
>
> What I don't understand is why is /home so tiny and how can I
re-partition
> this without having to nuke and rebuild my machine?
I doubt anyone can tell you why /home is so tiny.  But depending on the
filesystem used, you may be able to resize on the fly, without even
needing a reboot.  The LVM HOWTO is a bit out of date, but describes the
process here:

http://www.tldp.org/HOWTO/LVM-HOWTO/extendlv.html

Growing XFS filesystems online is required; they can't be grown offline.
Growing ext4 online should be easy, but I've only tested it once in
CentOS 6.  As Timo notes, you should have a backup before proceeding in
any case.

I believe there are GUI tools to manipulate LVM and filesystems
(system-config-lvm IIRC), but I haven't used this tool so can't give you
any helpful guidance.

You can put everything on one filesystem if you wish.  This is mostly a
matter of personal taste for many desktop uses (and some server uses).

--keith



-- 
kkeller at wombat.san-francisco.ca.us

On 4/1/2013 12:00 PM, Yves S. Garret wrote:
> What I don't understand is why is /home so tiny and how can I
re-partition
> this without having to nuke and rebuild my machine?
what do you get from

     # vgs

?

if there's VFree, you can lvextend the backing LV behind /home, then 
grow the file system to use that additional space.

# lvextend -L +8G vg_ysg/lv_home
# resize2fs /home

if there's no VFree, and you want everything in /   you could reboot to 
single user mode, and do something like...

# cd /
# mkdir /home2
# mv /home/* /home2       # this will take awhile
# umount /home
# rmdir /home
# mv /home2 /home

and vi /etc/fstab and remove the mount for /home

now, you can lvremove vg_ysg/lv_home   to free up the space it used 
(will probably need a --force), then lvextend the vg_ysg/lv_root volume, 
and grow /that/ file system to suit.

note.  I typed all that off the top of my head.  TRUST NOTHING, VERIFY 
EVERYTHING, UNDERSTAND THE MEANING OF EVERY COMMAND YOU ARE DOING!!!  
Caveat Emptor.




-- 
john r pierce                                      37N 122W
somewhere on the middle of the left coast