installer or initramfs-tools crashes when size of /boot is too small -- warn/disallow?

[Martin Pitt]

I got this crash on today's (20151014) amd64 wily desktop image while trying to reproduce bug 1506139. I did a manual partitioning with this layout:

Partition 1: plain ext4 boot partition mounted on /boot
Partition 2: luks-encrypted swap
Partition 3: luks-encrypted btrfs for /

and auto-login (should hardly matter).

The installer crashed with this initramfs-tools error (and an unclose-able error window in ubiquity).

ProblemType: Package
DistroRelease: Ubuntu 15.10
Package: initramfs-tools 0.120ubuntu6
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
ApportVersion: 2.19.1-0ubuntu2
Architecture: amd64
CasperVersion: 1.365
Date: Thu Oct 15 09:52:45 2015
DuplicateSignature: package:initramfs-tools:0.120ubuntu6 [modified: usr/sbin/update-initramfs]:subprocess installed post-installation script returned error exit status 1
ErrorMessage: subprocess installed post-installation script returned error exit status 1
LiveMediaBuild: Ubuntu 15.10 "Wily Werewolf" - Alpha amd64 (20151014)
PackageArchitecture: all
RelatedPackageVersions:
 dpkg 1.18.2ubuntu4
 apt 1.0.10.2ubuntu1
SourcePackage: initramfs-tools
Title: package initramfs-tools 0.120ubuntu6 [modified: usr/sbin/update-initramfs] failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Martin Pitt (pitti)]

Processing triggers for initramfs-tools (0.120ubuntu6) ...
update-initramfs: Generating /boot/initrd.img-4.2.0-16-generic
Warning: /sbin/fsck.btrfs doesn't exist, can't install to initramfs, ignoring.

gzip: stdout: No space left on device
E: mkinitramfs failure cpio 141 gzip 1
update-initramfs: failed for /boot/initrd.img-4.2.0-16-generic with 1.

Eh -- I meant to type "1000" MB for /boot, not "100", sorry. Changing to a low-prio ubiquity bug, it couldn't hurt to warn about/disallow to small /boot size.

[Phillip Susi (psusi)]

100 mb should be plenty to finish the install. This used to be enough for two kernels at once.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Draget (dragetd)]

Stumbled over the same issue.

It failed with 128MB site for /boot but worked with 150MB size.

What is this package unpacking that 128MB is not enough?! I also noticed that after the initial error messagesbox that tells you about initramfs-tools, there is another one (maybe from the finished installation in the background?) that shows that dpkg faild with exitcode (1) due to the following packages: -> and then no package is listed.

Seems like this error-reporting also did not work.

[Draget (dragetd)]

I need to update what I just posted.

Installing with 160MB /boot size works, but sends errors and application crashes just after you do your first system upgrade.

The kernel and some stuff needs about 10-20MB. The initramfs almost 60MB. When there is an old kernel plus a new one installed, this doubles to ~150MB space required. But when the initramfs is being rebuild because of some module update, it is being rebuild in a temporary file on /boot!

It would be better if this one was assembled on /tmp instead and then move to boot.

This requires an additional 60MB of space. So the bare minimum required to function is somewhere around 210MB. Add some filesystem overhead etc. and you need to create at least a 256MB /boot partition. If you do not clean up your older kernels right away, you should even go for 512MB. The installer should warn under 512MB that it requires at least 256MB and recommends 512MB.