How to reduce LVM filesystem in Linux

Unlike growing the filesystem, reducing the filesystem should be practiced carefully. In the example below, we will see - how to reduce LVM filesystem using the lvreduce command.

System utilities used:

1. lsblk 2. df 3. lsof 4. du 5. umount/mount 6. lvreduce

Follow the steps outlined below to reduce the logical volume:

1. Make sure that the device is readable by the Operating System

# lsblk

2. Verify filesystem’s type e.g. ext4:

# df -Th

3. Verify if there is a running process on top of the affected filesystems:

# lsof [directory mounpoint]

4. Unmount all filesystems on top of the affected directory:

# umount [directory]

5. Verify the size of the affected directory:

# du -sh

6. Unmount the affected directory:

# umount [directory]

7. Reduce the affected directory:

# lvreduce -L [size] -r [logical volume device]

8.Mount all back previously unmounted filesystems:

# mount [directory]