How to Reduce lvm partition in CentOS 7

Sometimes when we are facing issue with high space utilization of the disk in Linux system, then we can make some space by reducing the lvm partition which have unused space available if hard disk partitioned in lvm. Reducing the lvm volume cannot be done online, the volume should be unmounted while reducing. Reducing the logical volume is the risk of data lose and it is always recommended to make a backup of data before reducing the volume. 

This article describes How to Reduce lvm partition in CentOS 7.

 

Here we are using lv_home logical volume to reduce 5 GB of space out of 15 GB as shown below: 

 

[root@linuxcnf ~]# df -hT /home/ Filesystem                      Type  Size  Used Avail Use% Mounted on /dev/mapper/vg_linuxcnf-lv_home ext4   15G   41M   14G   1% /home [root@linuxcnf ~]#

 

Step 1. Unmount the File System: Run the following command to unmount the file system:

 

[root@linuxcnf ~]# umount /home/ [root@linuxcnf ~]#

 

Step 2. Check the File System: Run the following command to check the file system error if any:

 

[root@linuxcnf ~]# e2fsck -f /dev/mapper/vg_linuxcnf-lv_home e2fsck 1.42.9 (28-Dec-2013) 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_linuxcnf-lv_home: 11/983040 files (0.0% non-contiguous), 104724/3932160 blocks [root@linuxcnf ~]#

 

Step 3. Reduce the File System: Run the following command to resize the file system before reducing lvm volume:

 

[root@linuxcnf ~]# resize2fs /dev/mapper/vg_linuxcnf-lv_home 10G resize2fs 1.42.9 (28-Dec-2013) Resizing the filesystem on /dev/mapper/vg_linuxcnf-lv_home to 2621440 (4k) blocks. The filesystem on /dev/mapper/vg_linuxcnf-lv_home is now 2621440 blocks long.   [root@linuxcnf ~]#

 

Step 4. Reduce the Volume: Run the following command to reduce the lvm volume:

 

[root@linuxcnf ~]# lvreduce -L 10G /dev/mapper/vg_linuxcnf-lv_home   WARNING: Reducing active logical volume to 10.00 GiB.   THIS MAY DESTROY YOUR DATA (filesystem etc.) Do you really want to reduce vg_linuxcnf/lv_home? [y/n]: y   Size of logical volume vg_linuxcnf/lv_home changed from 15.00 GiB (3840 extents) to 10.00 GiB (2560 extents).   Logical volume vg_linuxcnf/lv_home successfully resized. [root@linuxcnf ~]#

 

Step 5. Check the File System: Run the following command to check the file system error if any:

 

[root@linuxcnf ~]# e2fsck -f /dev/mapper/vg_linuxcnf-lv_home e2fsck 1.42.9 (28-Dec-2013) 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_linuxcnf-lv_home: 11/655360 files (0.0% non-contiguous), 83137/2621440 blocks [root@linuxcnf ~]#

 

Step 6. Mount the File System & Validate: Run the following command to check the file system error if any:

 

[root@linuxcnf ~]# mount /home/ [root@linuxcnf ~]# df -h /home/ Filesystem                       Size  Used Avail Use% Mounted on /dev/mapper/vg_linuxcnf-lv_home  9.8G   37M  9.2G   1% /home [root@linuxcnf ~]# [root@linuxcnf ~]# vgs   VG          #PV #LV #SN Attr   VSize  VFree   vg_linuxcnf   1   4   0 wz--n- 38.99g 5.00g [root@linuxcnf ~]#

 

Done!!! /home partition is resized successfully and now 5GB free space available in volume group vg_linuxcnf.