I was trying to upgrade from 20.10 to 21.04. I fully updated the system (no reboot was required), then ran do-release-upgrade:
Checking for a new Ubuntu release
Get:1 Upgrade tool signature [819 B]
Get:2 Upgrade tool [1.276 kB]
Fetched 1.276 kB in 0s (0 B/s)
authenticate 'hirsute.tar.gz' against 'hirsute.tar.gz.gpg'
extracting 'hirsute.tar.gz'
Reading cache
Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done
Get:1 http://at.archive.ubuntu.com/ubuntu hirsute InRelease [269 kB]
...
In the end there was not enough space on /boot to continue:
Calculating the changes
Not enough free disk space
The upgrade has aborted. The upgrade needs a total of 151 M free
space on disk '/boot'. Please free at least an additional 8.464 k of
disk space on '/boot'. You can remove old kernels using 'sudo apt
autoremove' and you could also set COMPRESS=xz in
/etc/initramfs-tools/initramfs.conf to reduce the size of your
initramfs.
Restoring original system state
Aborting
Reading package lists... Done
Building dependency tree
Reading state information... Done
My /boot is tiny (237M); Ubuntu's installer created it this way 5 years ago. There was only the current kernel left, and I'm already using COMPRESS=xz for the initramfs, so I had to remove memtest86+ to make some space. Then I re-ran do-release-upgrade:
root@hostname:/boot # do-release-upgrade
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.
root@hostname:/boot # apt update
Get:1 http://at.archive.ubuntu.com/ubuntu hirsute InRelease [269 kB]
Get:2 http://at.archive.ubuntu.com/ubuntu hirsute-updates InRelease [109 kB]
Get:3 http://at.archive.ubuntu.com/ubuntu hirsute-backports InRelease [90,7 kB]
Get:4 http://security.ubuntu.com/ubuntu hirsute-security InRelease [101 kB]
Get:5 http://at.archive.ubuntu.com/ubuntu hirsute-updates/main amd64 Packages [238 kB]
Get:6 http://at.archive.ubuntu.com/ubuntu hirsute-updates/main i386 Packages [124 kB]
Get:7 http://at.archive.ubuntu.com/ubuntu hirsute-updates/main amd64 c-n-f Metadata [4.744 B]
Fetched 936 kB in 1s (1.066 kB/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done
2633 packages can be upgraded. Run 'apt list --upgradable' to see them.
This can't be right. Those 2633 packages must be from 21.04, and the updater did not restore the previous system state.
How should I continue? I don't think it's safe to just let apt upgrade all those packages and hope for the best...
