Comment 74 for bug 1619188

The tests started yesterday can be described like this:

1. I tested the Ubuntu 16.04.1 LTS desktop amd64 iso file.

2. To be completely sure, I created two USB boot drives with the Ubuntu Startup Disk Creator (not that it would clone differently from mkusb, but anyway, just in case.

3. I upgraded casper to the new version in xenial-proposed, 1.376.2.

4. I ran both tests in UEFI mode, a live-only session in an Intel NUC

https://www-ssl.intel.com/content/www/us/en/nuc/nuc-kit-nuc6i3syh.html

and a persistent live session in a Lenovo X131e

https://shop.lenovo.com/ISS_Static/ww/wci/products/us/laptop/thinkpad/x-series/x131e-intel/X131e-Datasheet-Intel.pdf

The persistence was using a casper-rw partition in another drive (because the cloned drive has the read-only file system ISO 9660.

I checked with 'df -h' how much space was used before and after the test period.

5. Result

Live-only:

ubuntu@ubuntu:~$ date;df -h .
Wed Oct 26 17:46:20 UTC 2016
Filesystem Size Used Avail Use% Mounted on
/cow 1.9G 48M 1.9G 3% /
ubuntu@ubuntu:~$ echo 'this is live-only'
this is live-only
ubuntu@ubuntu:~$ echo 'this is live-only'
this is live-only
ubuntu@ubuntu:~$ date;df -h .
Wed Oct 26 19:38:35 UTC 2016
Filesystem Size Used Avail Use% Mounted on
/cow 1.9G 48M 1.9G 3% /
ubuntu@ubuntu:~$ date;df -h .
Thu Oct 27 16:30:19 UTC 2016
Filesystem Size Used Avail Use% Mounted on
/cow 1.9G 1.1G 886M 54% /
ubuntu@ubuntu:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 1.9G 0 1.9G 0% /dev
tmpfs 384M 6.4M 378M 2% /run
/dev/sdb 1.5G 1.5G 0 100% /cdrom
/dev/loop0 1.4G 1.4G 0 100% /rofs
/cow 1.9G 1.1G 886M 54% /
tmpfs 1.9G 172K 1.9G 1% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
tmpfs 1.9G 4.0K 1.9G 1% /tmp
tmpfs 384M 124K 384M 1% /run/user/999
/dev/mmcblk0p2 6.0M 0 6.0M 0% /media/ubuntu/Firmware

Persistent live:

ubuntu@ubuntu:~$ date;df -h .
Wed Oct 26 18:39:29 UTC 2016
Filesystem Size Used Avail Use% Mounted on
/cow 22G 92M 21G 1% /
ubuntu@ubuntu:~$ date;df -h .
Thu Oct 27 16:29:50 UTC 2016
Filesystem Size Used Avail Use% Mounted on
/cow 22G 1.1G 20G 6% /
ubuntu@ubuntu:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 1.9G 0 1.9G 0% /dev
tmpfs 380M 6.2M 374M 2% /run
/dev/sda 1.5G 1.5G 0 100% /cdrom
/dev/loop0 1.4G 1.4G 0 100% /rofs
/cow 22G 1.1G 20G 6% /
tmpfs 1.9G 228K 1.9G 1% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
tmpfs 1.9G 4.0K 1.9G 1% /tmp
tmpfs 380M 92K 380M 1% /run/user/999
/dev/mmcblk0p5 22G 1.1G 20G 6% /media/ubuntu/casper-rw
/dev/mmcblk0p3 6.4G 2.1G 4.0G 34% /media/ubuntu/root

6. Conclusion

In both cases, a big unattended upgrade was performed. The used space increased

from 48M to 1.1G in the live-only case and
from 92M to 1.1G in the persistent live case.

I attach the terminal dialogues in both cases for more details (in this comment and the next one).