In this tutorial, I will show you how to reduce EBS volume size in AWS using an Ubuntu Linux instance. In this example, I have 25GB root volume and try to decrease it to 8GB.
1. Login to AWS management consoles and stop the instance.
2. Select the volume attached to this instance and detach it.
3. Select the detached volume and create a snapshot.
4. Create a new volume in the same availability zone of your instance of the preferred size. This volume will eventually replace your current volume.
5. Create another new volume from a snapshot which has been we have created in Step 3. Make sure you need to create in same availability zone.
So finally we have 3 volume now. one is the original volume, the second one is new created (reduce size) volume and, the third one is created from a snapshot.
6. Now Reattach the three volumes to an instance as described below.
Original volume at /dev/sda1
new volume at /dev/sdf
snapshot at /dev/sdg
7. Restart the instance and sign in with SSH. Create a filesystem on the new volume using mkfs.ext4
8. it generates the following output
9. Create mount points for snapshot, new volume and mount them using below commands.
1. Login to AWS management consoles and stop the instance.
3. Select the detached volume and create a snapshot.
4. Create a new volume in the same availability zone of your instance of the preferred size. This volume will eventually replace your current volume.
5. Create another new volume from a snapshot which has been we have created in Step 3. Make sure you need to create in same availability zone.
6. Now Reattach the three volumes to an instance as described below.
Original volume at /dev/sda1
new volume at /dev/sdf
snapshot at /dev/sdg
7. Restart the instance and sign in with SSH. Create a filesystem on the new volume using mkfs.ext4
sudo mkfs.ext4 /dev/xvdf
8. it generates the following output
9. Create mount points for snapshot, new volume and mount them using below commands.
sudo mkdir /mnt/newvol
sudo mkdir /mnt/snapshot
sudo mount /dev/xvdf /mnt/newvol
sudo mount -t ext4 /dev/xvdg1 /mnt/snapshot
10. Find the filesystem label of the original volume, so as to change the same for a new volume.
sudo e2label /dev/xvda1
11. Set this as the label for the new volume.
sudo e2label /dev/xvdf cloudimg-rootfs
12. Now, copy all data from the snapshot to new volume using rsync command.
sudo rsync -avx /mnt/snapshot/ /mnt/newvol/
13. Install grub on a new volume using below command
sudo grub-install --root-directory=/mnt/newvol/ --force /dev/xvdf
14. Unmount the new volume
sudo umount /mnt/newvol
15. Freshly check filesystem
sudo e2fsck -f /dev/xvdf
16. Change UUID insert below command.
blkid
/dev/xvda1: LABEL="cloudimg-rootfs" UUID="bbf64c6d-bc15-4ae0-aa4c-608fd9820d95" TYPE="ext4" PARTUUID="9f3e4931-01"
Copy the UUID string from the result of blkid (the one for original volume /dev/xvda) and use it with tune2fs, replacing <uuid> below,
Change <uuid> with real UUID.sudo tune2fs -U<uuid>/dev/xvdf
17. Freshly check again filesystem
e2fsck -f /dev/xvdf
18. Notes: if tune2fs fails to change the UUID, you may need to unset uninit_bg flag* on the new volume, before trying the same command again.
sudo tune2fs -O ^uninit_bg /dev/xvdf
19. Now Sign out from SSH and Stop Instance from AWS management console
20. Detach All three volume from the instance
21. Attach new volume (reduced size) at /dev/sda1
22. Start the instance and check.
23. if all things are good, then delete remaining two EBS volumes, which are no need more. Also, delete snapshot which we have taken in Step 3.
