Hi,
I would like to shrink my lv_root from 9.54g to 8g safely. This is a SL6.3 vm running on SL6.3 base box. I tried "single" from grub and booted the box but lv_root gets mounted automatically so I didn't run any disk related commands to prevent loss of data.

This is my current disk layout:
[root@outsider1 ~]# lvs
LV VG Attr LSize Pool Origin Data% Move Log Copy% Convert
lv_root vg_outsider1 -wi-ao-- 9.54g
lv_swap vg_outsider1 -wi-ao-- 1.97g
[root@outsider1 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/vda2 vg_outsider1 lvm2 a-- 11.51g 0
[root@outsider1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_outsider1-lv_root
9.4G 2.3G 6.7G 26% /
tmpfs 499M 0 499M 0% /dev/shm
/dev/vda1 485M 33M 427M 8% /boot
[root@outsider1 ~]#

Read over http://www.linuxquestions.org/questi...volume-337823/

This is a reason why I never make my root/boot partitions logical. You will need to boot off of a live cd with lvm2 support.

1 members found this post helpful.

''



Thanks but I need to make this change on a VM. I am not sure how I can do this on a VM. How to boot a VM on rescue/ or using live cd?

Try Section 2 linux.dell.com/files/whitepapers/KVM_Virtualization_in_RHEL_6_Made_Easy_Part2.pdf (HOWTO rescue VM)

1 members found this post helpful.

I found a way to boot the VM using resuce mode and was successful with shrinking the size of lv_root safely following the steps provided by Kustom42 member. Thanks.

# yum install libguestfs-tools
# virt-rescue -d vm-name

><rescue> vgs
VG #PV #LV #SN Attr VSize VFree
vg_outsider1 1 2 0 wz--n- 11.51g 0

><rescue> lvm vgchange -ay
2 logical volume(s) in volume group "vg_outsider1" now active

><rescue> e2fsck -f /dev/mapper/vg_outsider1-lv_root
e2fsck 1.41.12 (17-May-2010)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/mapper/vg_outsider1-lv_root: 50262/625856 files (0.2% non-contiguous), 464559/2500608 blocks

><rescue> resize2fs -f /dev/mapper/vg_outsider1-lv_root 8G
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/mapper/vg_outsider1-lv_root to 2097152 (4k) blocks.
The filesystem on /dev/mapper/vg_outsider1-lv_root is now 2097152 blocks long.

><rescue> lvreduce -L 8G /dev/mapper/vg_outsider1-lv_root
WARNING: Reducing active logical volume to 8.00 GiB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce lv_root? [y/n]: y
Reducing logical volume lv_root to 8.00 GiB
Logical volume lv_root successfully resized

><rescue> exit
exit

virt-rescue: Syncing the disk now before exiting ...

[ 366.112306] md: stopping all md devices.
[ 366.213614] Restarting system.
[ 366.214264] machine restart

Thanks Chris. I followed those steps.