Recently I had to reinstall a system at office with Debian Wheezy and
I thought I should use this opportunity to experiment with LVM. Yeah
I've not used LVM till date, even though I'm using Linux for more than
5 years now. I know many DD friends who use LVM with LUKS encryption
and I always wanted to experiment, but since my laptop is only thing
I've and its currently perfectly in shape I didn't dare to experiment
it there. This reinstall was golden opportunity for me to experiment
and learn something new.
I used Wheezy CD ISO downloaded using jigdo for installation. Now I
will just go bit off topic and want to share the USB stick
preparation. I have to say this because I had not done installation
for quite a while now. Last I did was during Squeeze time so like
usual I blindly executed following command.
Surprisingly USB stick didn't boot! I was getting Corrupt or missing
ISO.bin. So next I tried using dd for preparing.
Surprisingly this also didn't work and I get same error message as
above. This is when I went back to debian manual and looked for
installation step and there I found new way!
Look at destination, its a device and voilà this worked! This is
something new I learnt and I'm surprised how easy it is now to prepare
USB stick. But I still didn't get why first 2 methods failed!. If you
guys know please do share.
Now coming back to LVM. I used default LVM when disk partitioning was
asked, and I used guided partitioning method provided by
debian-installer and ended up with following layout
So guided partitioning of debian-installer allocates 10G for root
and rest to home and swap. This is not a problem but when I started
installing required software, I could see root running out of space
quickly so I wanted to resize root and give it 10G more, for this I
need to reduce the home by 10G for which I need to first unmount the
home partition. Unmounting home from running system isn't possible so
I booted into recovery assuming I can unmount home there but I
couldn't. lsof didn't show any one using /home after searching a bit
I found fuser command and it looks like kernel is using /home which
is mounted by it.
So it isn't possible to unmount /home in recovery mode also. Online
materials told me to use live-cd for doing this but I didn't have
patience to do that so I just went ahead commented /home mounting in
/etc/fstab and rebooted!. This time it worked and /home is not mounted
on recovery mode. Now comes the hard part resizing home, thanks to
TLDP doc on reducing I coud do this with
following step
And now the next part live extending the root partition again thanks
to TLDP doc on extending following command
did it.
And now important part! Uncomment /home line in /etc/fstab so it
will be mounted normally in next boot and reboot! On login I can see
my partitions updated.
I've started liking LVM more now! :)