Unattended upgrades can break persistent live media
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
casper (Ubuntu) |
Fix Released
|
Medium
|
Brian Murray | ||
Xenial |
Fix Released
|
Medium
|
Brian Murray | ||
Yakkety |
Fix Released
|
Medium
|
Brian Murray |
Bug Description
Test Case
---------
1) Boot an Ubuntu 16.04 Live CD
2) Choose Try Ubuntu
3) head -n5 /etc/apt/
4) Observe -security is enabled in line 3. (// is a comment)
5) Run /usr/lib/
6) Observe your Live environment run out of space! (I received a pop-up re lack of free space and /var/log/
With the version of the package in -proposed step 4 will reveal the -security pocket being disabled and step 6 won't fill your live environment.
Regression Potential
-------
Persistent live users will not receive updates from -security, but that seems less bad than destroying people's live environment by filling up their disk.
Original Bug Description
-------
Looking at the persistent live Ubuntu 16.04 LTS system - the Software & Updates screen / Update - I notice, that Automatic updates is set to 'Download and install automatically'. This is bad in a persistent live system.
After leaving the persistent live Ubuntu 16.04 LTS system running overnight, I found that it had performed an automatic upgrade:
df revealed that the content in casper-rw had increased to 1.6 GiB.
It was a surprise that the persistent live system started an automatic upgrade. This is not caused by the installer (mkusb), because the files controlling those actions are not touched. Instead it is caused by a change of the default action, when there are security updates. And the survey indicates that this default setting is different between the flavours and versions of Ubuntu. Lubuntu keeps the setting 'Display immediately', while the other tested flavours change it from 14.04 LTS to 16.04 LTS.
Until this is resolved, it is a good idea to disable unattended-upgrades manually, but above all, to take regular backups, when you use a persistent live system.
The survey is described in this link to the Ubuntu Forums:
https:/
and it contains some screenshots illustrating the settings manager for automatic updates for different versions and flavours of Ubuntu.
-o-
There are various scripts in the casper package that change things to be more appropriate for the live environment. I suggest to change the default for security updates to 'Display immediately', when the system is running live and persistent live.
See also this link to Ask Ubuntu, the first report about this problem:
https:/
-o-
Addendum: Things should continue to work if you leave a live Ubuntu iso running for a day or two. Unattended upgrades cause problems for all live systems, 'live-only' and 'persistent live'.
ProblemType: BugDistroRelease: Ubuntu 16.04
Package: casper 1.376
ProcVersionSign
Uname: Linux 4.4.0-31-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CasperVersion: 1.376
CurrentDesktop: Unity
Date: Thu Sep 1 08:32:08 2016
LiveMediaBuild: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
ProcEnviron:
TERM=xterm-
PATH=(custom, no user)
XDG_RUNTIME_
LANG=en_US.UTF-8
SHELL=
UpgradeStatus: No upgrade log present (probably fresh install)
description: | updated |
tags: | added: rls-y-incoming |
description: | updated |
description: | updated |
tags: | removed: rls-y-incoming |
Changed in casper (Ubuntu Yakkety): | |
status: | Confirmed → Triaged |
Changed in casper (Ubuntu Yakkety): | |
assignee: | nobody → Brian Murray (brian-murray) |
status: | Triaged → In Progress |
Changed in casper (Ubuntu Xenial): | |
status: | Triaged → In Progress |
description: | updated |
description: | updated |
tags: |
added: verification-failed removed: verification-needed |
- This bug affects 16.04 LTS, 16.04.1 LTS and Yakkety.
- Several flavours are affected.
- Lubuntu is not affected.
One screenshot is attached here. You find more screenshots at
https:/ /ubuntuforums. org/showthread. php?t=2335669& p=13538805# post13538805