topic Re: lvm & resize in Operating System - Linux

lvm & resize

Josef Forman — Wed, 21 Jul 2004 09:24:35 GMT

How can I change size of my LV (reiser and ext3) without loosing data?

Re: lvm & resize

Steven E. Protter — Wed, 21 Jul 2004 09:43:02 GMT

If you are using lvm for disk managment, the command is lvreduce.

Helpful hints
1) Back up your data before you start, if you squeeze too hard, you'll hammer your data.

SEP

Re: lvm & resize

Jerome Henry — Wed, 21 Jul 2004 10:08:27 GMT

Extending is most of the time ok :
lvextend -L +50M /dev/vgname/lvname
or
lvextend -L 450M /dev/vgname/lvname

Where vgname is your group volume name, and lvname your Logical volume name.
You can use the +50M (say) to increase for 50 M, or put directly required new size.

SAme with lvreduce, but it's safer to backup, as it's supposed to be safe if you reduce to a size larger than your data volume, but it happends that datas are altered...

hth

Jerome Henry

Re: lvm & resize

Jan Sladky — Wed, 21 Jul 2004 10:39:41 GMT

hi AliG,
what do you mean by the change of size - extending fs or reducing ? I have some hints for reiserfs:

BACKUP YOUR DATA FIRST

In case of Reiser extending:
1.vgdiplay -v #check free space on currentVG
2.lvextend -L +6G /dev/vg00/lv00
3.resize_reiserfs /dev/vg00/lv00

In case of Reiser reducing ON value:
1.reduce the size of fs:
resize_reiserfs -s-2048M -f /dev/vg02/lv00

2.reduce size of LV
lvreduce -L-2G /dev/vg02/lv00

Be carefful, although you can do resizing on mounted fs, it is safer to do it on unmounted.

br Jan

Re: lvm & resize

Marco Di Ianni — Thu, 29 Jul 2004 10:40:31 GMT

What do you want to do?!?!
Do you want extend or reduce logical volume?!

If you want extend the command is:

# lvextend -L 500 /dev/vg_name/lv_name

where 500 is the new size of volume

If you want reduce the LV is:

# lvreduce -L 500 /dev/vg_name/lv_name

(BACKUP YOUR DATA BEFORE REDUCE LV!!)

Bye!

Re: lvm & resize

Josef Forman — Fri, 30 Jul 2004 02:54:31 GMT

I need to extend my LV from 100GB to 150GB. Is it safe or i should backup too?

PF

Re: lvm & resize

Marco Di Ianni — Fri, 30 Jul 2004 09:10:03 GMT

No.....for extend operation you don't need to backup data, this operation is not dangerous! Don't worry!

Re: lvm & resize

Steven E. Protter — Fri, 30 Jul 2004 12:04:42 GMT

I would back up the data prior to the extend

There are rare cases on hp-ux (from whece lvm comes), where an extend failed and corrupted the filesystem.

Extending a logical volume is much safer than trying to make it smaller.

The process is:

lvextend -L /name_of_lvol /disk
umount the filesystem
extendfs

SEP