Run do-release-upgrade to ubuntu 21.10

Looks like a simple task, but ending with many things to do...

No screen

After run do-release-upgrade, I went to sleep, then ssh connection dropped due to iMac auto sleep. The installation stopped at asking question of grub installation.

When I check the process, got a process similar to below one, which is still at pts/1, which means the process is still running at another virtual terminal.

/usr/bin/python3 /tmp/ubuntu-release-upgrader-qzt422az/focal --mode=server --frontend=DistUpgradeViewText

When I try to run do-release-upgrade again, got following message.

# do-release-upgrade 
Checking for a new Ubuntu release
No new release found.

Then I try to run apt install screen, says apt is locked by process nnnn.

As suggested by others, I killed the process nnnn, and run following command, then the terminal change to installation virtual screen, and continued.

dpkg --configure -a

Error on grub-efi

Then got following error

# dpkg --configure -a
Setting up grub-efi-amd64-signed (1.173+2.04-1ubuntu47) ...
NTFS signature is missing.
Failed to mount '/dev/sda1': Invalid argument
The device '/dev/sda1' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?
dpkg: error processing package grub-efi-amd64-signed (--configure):
 installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 12
Errors were encountered while processing:
 grub-efi-amd64-signed

As suggested by others, I ran following commands, which remove grub2 and install grub, then no error any more.

Note: do backup of /etc/default/grub, and verify the contents. I didn't do this, caused more issues later

apt-get purge grub\*
sudo apt-get install grub-efi
sudo apt-get autoremove
sudo update-grub

No zpool found during reboot

The system go into initramfs mode after reboot, looks like iSCSI devices not found.

Then I booted from CD again, and found that iSCSI configuration in /etc/default/grub was missing.

After login to iSCSI, I mirror back the bpool and rpool back to local disk, and run following command to fix it.

update-initramfs -v -k $(uname -r) -c
update-grub

Forgot waiting for resilvering finish

Forgot wait for zpool sync finish, the I rebooted the server.

Note: Some people said it is ok, but my case is NOT OK.

After perform zpool resync again, got following error with local partition CKSUM = 1.

One or more devices has experienced an unrecoverable error.

This was caused by reboot, just perform following command to clean the flag.

zpool clear rpool

Booting hung

This is an old issue, caused by network shutdown before iSCSI drive dismount. Run following command,

systemctl edit --full open-iscsi.service

Comment out the following line

#ExecStop=/lib/open-iscsi/logout-all.sh

References

Sub-process /usr/bin/dpkg returned an error code (1)