Upgrade Kubuntu from 23.04 to 23.10 - hangs

[graemev]

Following a complex issue due to a too small /boot. I tried again to upgrade.


It ran for a very long while, ending in:

update-initramfs: deferring update (trigger activated)
Sourcing file `/etc/default/grub'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-6.5.0-10-generic
Found linux image: /boot/vmlinuz-6.2.0-36-generic
Found initrd image: /boot/initrd.img-6.2.0-36-generic
Found linux image: /boot/vmlinuz-6.2.0-35-generic
Found initrd image: /boot/initrd.img-6.2.0-35-generic
Found memtest86+x64 image: /boot/memtest86+x64.bin
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
​

Just before this a popup appeared saying a filesystem was not responding ...

So after being hung for about an hour , I had to shut the system down .... at reboot it failed:

Kernel Panic .... Unable to mount root fs on unknown-block(0,0) ....

Likely the initrd (or similar) was not setup (given where it hung)

As a happy accident, due to my earlier issues with /boot, I had a whole alternate partition with boot loader that was able to boot
(old kernel vmlinuz-6.2.0-36-generic) and was able to run:

sudo dpkg --configure -a

(I didn't guess, I got prompted

E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.

)
This ran for a while, the the same popup and again it hung:

Configuring grub-pc
-------------------

A new version (/tmp/grub.f9D62sso8z) of configuration file /etc/default/grub is available, but the version installed
currently has been locally modified.

1. install the package maintainer's version 5. show a 3-way difference between available versions
2. keep the local version currently installed 6. do a 3-way merge between available versions
3. show the differences between the versions 7. start a new shell to examine the situation
4. show a side-by-side difference between the versions

What do you want to do about modified configuration file grub? 1


Replacing config file /etc/default/grub with new version
Sourcing file `/etc/default/grub'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-6.5.0-10-generic
Found initrd image: /boot/initrd.img-6.5.0-10-generic
Found linux image: /boot/vmlinuz-6.2.0-36-generic
Found initrd image: /boot/initrd.img-6.2.0-36-generic
Found linux image: /boot/vmlinuz-6.2.0-35-generic
Found initrd image: /boot/initrd.img-6.2.0-35-generic
Found memtest86+x64 image: /boot/memtest86+x64.bin
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
​

My guess was it was the automounted NFSv3 filesystems. This time I could not even shut it down:

init 6 failed , shutdown -n now , hung just before poweroff... so powerswitch

Again brought up using the alternate partition.

This time before attempting the dpkg --configure -a , I did:

systemctl stop autofs
systemctl stop nfs-client.target

And also disabled Wifi (vi GUI) [ As recommended the system had mains power and wired Ethernet throughout ]


Again kicked off :

sudo dpkg --configure -a

In the middle a couple of popups appeared that the Ethernet had disconnected & reconnected

And this time it completed cleanly.

So, if I were to guess I'd say the networking was stopped using the package reconfigure and this caused the whole process the hang (due of NFSv3 mounts blocking)