Boot partitions from installations prior to the 16.04 era are terribly small. When you install updates and encounter errors due to a full
/boot partition, consider risizing it.
If you can't do the steps described below, ask someone experienced to help you out.
This has worked 100% so far. 1 out of 1 tries. ;)
When there is some unpartitioned space on your drive, increasing the size of
/boot is actually very easy (even though the list below is rather long). It only takes a while.
sudo suto become root. We require root for everything.
ddto create an image of your encrypted partition. It will not be decrypted, so it is okay to store the image on an unencrypted device.
lsblkto list all drives.
sdaand usually contains
sda2(an extended partition) and
sda5(your crypted partition) inside
sdabelow; if yours is different, remember to use your drive label.
dd if=/dev/sda5 of=/media/something/sda5.dd bs=1Mto create an image of your encrypted partition.
ddprint its status by opening a 2nd terminal and sending the
pkill -USR1 dd.
sda5and select "Information". Note the drive's UUID and total sectors count (you may take a screenshot and save it to the external drive).
sda5and select "Delete". Confirm, and actually the delete the partition by clicking the tick icon in the icon bar.
sda2(not the empty space inside id) and select "Resize/Move". You can drag the partition to the end of your drive using the bar representation, or copy and cut the "Free space following" value and paste it to "Free space preceding". The "New size" should stay the same. Confirm and apply via the tick icon.
sda2and create a new partition. It does not matter which file system you choose.
sda5and select "Information".
sda2's size. Re-create
sda5until there are enough sectors.
dd if=/media/something/sda5.dd of=/dev/sda5 bs=1M
sda5to confirm its UUID has been restored. You should also see that sda5 is now a "crypt-luks" partition.
sda1and select "Resize/Move". You can now increase the size of
df -h /bootshould now show your boot partition's new size!
If anything goes wrong, try again by re-creating
sda5 and restoring your dd image.
Should everything fail, restore your image from the NAS using our backup drive's restore procedure.
This is more painful. You first need to shrink your encrypted partition.
You can then follow procedure A.