[Bug 1646222] Re: calculation of needed free space in /boot is inaccurate and causes refusal to upgrade

[Brian Murray]

I think part of the issue here is the function
estimate_kernel_size_in_boot, from utils.py, which does the following:

 92 def estimate_kernel_size_in_boot():
 93     """ estimate the amount of space that the current kernel takes in /boot """
 94     size = 0
 95     kver = os.uname()[2]
 96     for f in glob.glob("/boot/*%s*" % kver):
 97         size += os.path.getsize(f)
 98     return size

The glob ends up including vmlinuz and initrd, which is fine but then
DistUpgradeCache.py multiples size by 2.  We actually don't need enough
free space to accomadate for two of every kernel file in boot though.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to update-manager in Ubuntu.
https://bugs.launchpad.net/bugs/1646222

Title:
  calculation of needed free space in /boot is inaccurate and causes
  refusal to upgrade

Status in update-manager package in Ubuntu:
  New

Bug description:
  I have a /boot partition which is sized just right to accommodate 3
  kernels, plus a little bit of overhead.

  $ df -h /boot/
  Filesystem      Size  Used Avail Use% Mounted on
  /dev/sda5       280M  144M  118M  56% /boot
  $

  Previously, update-manager had no problem letting me upgrade kernels.
  With the latest kernel update in 16.10, I got an error message that I
  needed more free space on this filesystem.

  After bypassing update-manager with 'sudo apt dist-upgrade', the
  filesystem's usage looks like this:

  $ df -h /boot/
  Filesystem      Size  Used Avail Use% Mounted on
  /dev/sda5       280M  206M   56M  79% /boot
  $

  So update-manager is getting the disk usage requirement for /boot off
  by a factor of 2 (at least? I didn't save the error message from the
  dialog).

  It's better to refuse to upgrade than to fail mid-upgrade due to disk
  space, but not if that means getting stuck forever with an old kernel
  unnecessarily.

  ProblemType: Bug
  DistroRelease: Ubuntu 16.10
  Package: update-manager 1:16.10.7
  ProcVersionSignature: Ubuntu 4.8.0-27.29-generic 4.8.1
  Uname: Linux 4.8.0-27-generic x86_64
  ApportVersion: 2.20.3-0ubuntu8
  Architecture: amd64
  CurrentDesktop: Unity
  Date: Wed Nov 30 12:10:25 2016
  GsettingsChanges:
   b'com.ubuntu.update-manager' b'show-details' b'true'
   b'com.ubuntu.update-manager' b'window-height' b'551'
   b'com.ubuntu.update-manager' b'first-run' b'false'
   b'com.ubuntu.update-manager' b'window-width' b'813'
   b'com.ubuntu.update-manager' b'launch-time' b'1480522730'
  InstallationDate: Installed on 2010-09-24 (2259 days ago)
  InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release amd64 (20100816.1)
  PackageArchitecture: all
  SourcePackage: update-manager
  UpgradeStatus: Upgraded to yakkety on 2016-10-28 (32 days ago)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/1646222/+subscriptions