Testing Lubuntu live - Check for bug #1851123


Which tool/method are you using to create the live Lubuntu systems that you use for iso-testing?

I am asking because I want to check if/how Lubuntu live created that way is affected by

bug #1851123 ‘Ubuntu 19.10 and focal live cloned create and mount casper-rw partition’

If affected, I will ask you to confirm the bug in order to make the Ubuntu developers interested. I think the bug is located in casper.


My last command (listed in history) was

862 19/11/04 13:17:50 sudo dd bs=8M oflag=sync status=progress of=/dev/sdb if=/de2900/lubuntu_64/focal-desktop-amd64.iso

(bs=4M would more commonly be used & I usually don’t add the status detail)

Thanks, You are cloning. Then the main statement of the bug report is on the spot. Cloning with dd is risky, but when you do it the correct way it is a robust method and provides the same result as any other cloning method, for example with the Ubuntu Startup Disk Creator.

Please check when running live, if a casper-rw partition is created and if it is mounted as described in the bug report. And which is the big problem, if it is busy, so that it cannot be unmounted. I think you will find that it is the case, and I think confirming the bug helps getting the developers started.

I can’t currently look any further, but a quick look shows (part of fdisk -l & lsblk -fm output) using the latest 20.04 ‘live’


It matches my findings. lsblk shows /var/crash is the mountpoint.

If you run also df -h you will see that it shows /var/log is the mountpoint.

My result shows that it is possible to unmount /var/crash but not /var/log. This means that the live system, when booted with the boot option toram cannot unmount all partiitions and run without the boot drive connected. What is worse, we have lost the ability to boot live-only and repair the casper-rw partition. Now another linux system is necessary for that task, and it makes things more complicated for beginners.

Thanks for confirming the bug :slight_smile:

This bug is squashed in casper version 1.432, which comes with the Lubuntu Focal daily iso file 2019-11-14 :slight_smile:

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