Reduce partition size on EXT filesystems on Linux

It is possible to modify a partition size on EXT filesystem thanks to some few commands.

We will take here a simple example:

• We have a /dev/sda5 partition mounted on /home
• Its size is currently 150G and we want to reduce it to 100G

Let's check the current config (mounting point and size):Filesystem Size Used Avail Use% Mounted on
/dev/sda1 28G 3.3G 23G 8% /
/dev/sda2 477M 112M 341M 25% /boot
/dev/sda3 4.7G 12M 4.5G 1% /tmp
/dev/sda4 32G 470M 30G 2% /var
/dev/sda5 148G 87M 140G 1% /home
We need to first unmount the partition:# umount /dev/sda5
If you can't unmount it, double check what process is using it with the lsof command:# lsof /home
Then proceed with a check with e2fsck command and resize the partition with resize2fs by defining the new size (M for Megabytes, G for Gigabytes, and so on...)# e2fsck -f /dev/sda5
# resize2fs /dev/sda5 100G
Mount your partition back to your system:# mount /home
And check again your partition sizes :Filesystem Size Used Avail Use% Mounted on
/dev/sda1 28G 3.3G 23G 8% /
/dev/sda2 477M 112M 341M 25% /boot
/dev/sda3 4.7G 12M 4.5G 1% /tmp
/dev/sda4 32G 470M 30G 2% /var
/dev/sda5 99G 87M 94G 1% /home
We can see that the partition /home has now a size of 100G as expected!