Ubuntu – How to resize the partition in Ubuntu

There seems to be plenty of results on Google where people had similar problems. An example:

Back up all your important data before attempting this. Always assume that you can lose all your data when resizing partitions.

Shrink LVM without dataloss

This forum thread suggests the following procedure, in this example we shrink a partition from 10G to 9G:

First, we unmount.

sudo umount /dev/vg_blah/lv_blah

Check the file system.

sudo e2fsck -f /dev/vg_blah/lv_blah

Resize the file system and the logical volume. Doing this in one step can avoid mistakes which cause dataloss. (Note lvreduce parameter -L interprets G as 2^30 bytes and g as 10^9 bytes.)

sudo lvreduce --resizefs -L 9G /dev/vg_blah/lv_blah

(optional) Remove a physical drive from the volume group if desired (if you now have an unused drive).

sudo vgreduce vg_blah /dev/sdxy

All credit goes to brianmcgee.

Note: vgreduce will fail with cannot resize to xxxxx extents as later ones are allocated if you have another lv at the end of the disk - I had a swap lv, which I deleted. See How to shrink Ubuntu LVM logical and physical volumes? for help on that situation.

The Ubuntu partition sda5 is a secondary partition to the primary partition sda4 so you can't resize sda5 beyond the size of sda4

To resize the Ubuntu partition, you must first resize sda4 by extending it into the free space you have created. Then the next step is to extend sda5 to use up the extra spaces in sda4. You can do this in gparted and apply the change in one go.

Here are the steps:

1. Move the sda3 partition so that the free space is after sda3 (not before it like it is shown now).
2. Resize sda4 into the free space before it (by extending sda4). Be sure not to select sda5 by mistake as it is just an outline surrounding sda5.
3. Lastly, resize sda5 to fill up the larger sda4 partition you have created.
4. Now, apply the changes.

Good luck.

PS: Should backup important stuff in case things go wrong.