@nio-wiklund, @mwhudson : Thanks for your replies.

@nio-wiklund : Your solution would probably do the trick, but has the
inconvenient of indiscriminately replacing a string with another in the
whole image, hence possibly in places where it's not desired.

I think I will rather do one of those two things :

1. Create a partition that occupies the remaining space on the USB
stick, hence preventing the live image from creating (and writing to)
one without my consent

2. Create a custom Grub config file on the EFI partition on the stick,
specifying my own parameters

The first solution is the most straightforward, has the advantage the
stick can be used for additional purposes, but the inconvenient that
it's hardware-dependent (not all sticks have the same size). To have the
integrity check work, I would have to rehash after modifying, and
maintain different hashes, one hash per stick.

The second solution requires more changes, but would work for all
sticks. It probably won't work if I boot the stick on a non-EFI BIOS
though. For integrity-checking purposes I would have to rehash too, but
would only require one hash for all sticks.

Concerning your change proposal, adding an additional entry to Grub
solves indeed the problem of risking a typo compared to having to type
"nopersistent" and/or "toram" at every boot, to avoid undesired writes.
However, it still requires to never forget interrupting the boot
process.

@mwhudson : Imho, the current situation of the 19.10 live image can be
considered a bug, since it changes a default that has been there for
more than a decade, and that's in many minds, that a live OS image is
volatile.

That's not due to a coding error, like most bugs are, but rather in
comparison to usually expected behaviour, or "untold specification".

Moreover, your reasons for wanting it to become a default are unclear,
especially considering that the ones who want persistence could achieve
that by passing a one-time option at boot, and being OK for subsequent
boots, which obviously people who don't want persistence can't do,
precisely because they don't want persistence.

For these reasons it can be worth clarifying, outside of a bug process
why not. I just started a thread :
https://ubuntuforums.org/showthread.php?t=2431843

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1851123

Title:
  Ubuntu 19.10 and focal live cloned create and mount casper-rw
  partition

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1851123/+subscriptions

-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to