Shrink volume in Red Hat EL WS 4

araczek · 04-15-2009, 08:11 AM

Hello!

Okay, I am a Windows admin. That being said I want to shrink a Linux volume and I am having trouble. I really don't know my way around Linux. I found a procedure for LVM and it is not working out. I booted said Linux to rescue disk, did these commands:
>vgscan
>vgchange - a y VolGroup00
>vgmknodes
#e2fsck -f /dev/mapper/VolGroup00-LogVol00
#resize2fs /dev/mapper/VolGroup00-LogVol00 39GB
resize2fs 1.35 (28-Feb-2004)
resize2fs: bad filesystem size - 39GB

Does not matter what size I use (45, 50, 60 70) always same error.
What is wrong. I read somewhere maybe a newer version of resize2fs
would work? I don't know much about installing sw in Linux. Also this is a pretty much fresh out of box install except for different video drivers.

bhaslinux · 04-15-2009, 08:40 AM

can you try dropping the 'B' in GB ?
just give 39G

bhaslinux · 04-15-2009, 08:43 AM

and i guess you must be aware of what you are doing.
If you shrink the lv size, it will not appear as free space in the disk and you cannot create another partition
unless you are planning to shrink the PV itself - that is a very scary one to do!

araczek · 04-15-2009, 09:21 AM

Quote:

Originally Posted by bhaslinux

and i guess you must be aware of what you are doing.
If you shrink the lv size, it will not appear as free space in the disk and you cannot create another partition
unless you are planning to shrink the PV itself - that is a very scary one to do!

Okay, I am NOT aware of what I am doing! I had an idea maybe there was something else to do. Will pvresize work? I dug up a procedure but it says it's a tricky thing to do. See link:

http://fedorasolved.org/Members/zcat...-new-partition

Will this do? If there is a better way please detail what I need to do. Again, not a Linux guy.

...AR

bhaslinux · 04-15-2009, 09:37 AM

ok
for instances like this i always create multiple partitions and create PVS in those and merge them in a VG
if that was what done, we can just pvmove one of the PVs out and then create another patition
but that is not the case here i guess.

pvresize works ! but as i told already ... it is scary !
the link you had referred to is perfect link for this task.
But backup the data (atleast the important files) before doing anything to the PV.

More importantly

1. Just write down the partition cylinder starts and ends from the fdisk
2. Backup and keep the /etc/lvm/backup/VolGroup00 directory in a safe place and
easily accessible in case you need to restore the data

the good thing about LVM is you can easly restore the VGs and LVs from the VolGroup00 directory.