How to reduce the root partition in LVM

In this tutorial, I am using the CentOS6(I believe that its also applicable on other Linux distro but didn’t try yet) that has ext4 partition lv_root mounted as / and lv_swap as swap from the volume group vg_centos6 (which is default), that has two hard drives (66GB & 25GB). Due to some reasons, I want to remove the 25GB hard drive from my computer and want to add new 50 GB hard drive. Before, removing the hard drive from the computer, we need to resize the lv_root, then remove it from volume group and at the end from the physical volume.

WARNING: It’s really dangerous, so backup your data before attempting this. Please don’t blame me, if you destory your system. You are responsible for your own actions!

Check the size of  lv_root before starting this process:

df -h

0 Boot from CentOS 6 DVD (or any other Linux distro that you are using) and select “rescue” option: 1 Select the Skip, so that it will not mount the filesystem: 2 Run these commands:

vgchange -a y

3 Display the lv_root:

lvdisplay /dev/vg_centos6/lv_root

4 fsck on the large root filesystem (lv_root):

fsck.ext4 /dev/vg_centos6/lv_root

5 Run e2fsck with -f (force) option:

e2fsck -f /dev/vg_centos6/lv_root


Issue the resize2fs command to reduce the filesystem (Important: The size here is the actual/total size of the lv_root after reduce, not the size that we want to decrease):

resize2fs -p /dev/vg_centos6/lv_root 65G


Now, issue the lvreduce command to reduce the logical volume size:

lvreduce -L 65G /dev/vg_centos6/lv_root


Run lvdisplay command to confirm the change:

lvdisplay /dev/vg_centos6/lv_root


Reboot the system and login. Remove the disk (in my case it is, /dev/sdb1) from volume group and then from physical volume:

sudo vgreduce vg_centos6 /dev/sdb1

sudo pvremove /dev/sdb1


Check the size of  lv_root after all these changes:

df -h



Hope this will help you!

Please Remember me in your prayers!

9 responses to “How to reduce the root partition in LVM

  1. Puddleglum2014 July 28, 2014 at 4:08 am

    Thank you very much for these instructions, they did the trick and saved me hours of reinstalling the OS and a bunch of applications. I did this on CentOS 6.5

  2. marcopgordillo November 5, 2014 at 7:41 am

    Reblogged this on Marco Gordillo.

  3. Simon March 27, 2015 at 1:19 pm

    Thank you! Your instructions were very useful for me.

  4. Pingback: Resize partizione LVM | I'm Mr Uolf, I solve problems

  5. Christophe May 24, 2015 at 7:45 pm

    Very useful! thanks!

  6. Pingback: Unix/Linux:SSH: Shrinking root partition – Unix Questions

  7. Pingback: Basic Linux | Plesk Issues and fixes.

  8. Arunkumar Raju March 17, 2016 at 6:47 pm

    Thanks helped a lot

  9. Nail April 11, 2016 at 5:18 pm

    verified on centos 7 image

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