On one of my desktop machines, I decided it was time to update to 20.04 from 16.04. The installation is on a RAID1 with LVM2 on top. The initial update to 18.04 went smoothly using do-release-upgrade. The second upgrade to 20.04 choked though. A couple additional complications are that I have my /home mounted from NFS, but that won't enter in to the problematic bits here.
When I encountered the hitch in the update to 20.04 (some package conflict that was never very clear), I thought "okay, fine, my homedir is safely on NFS, the only other non-package files are on another logical volume, I'll just update the rootfs from the installer. Pretty quick, I was refamiliarized with the fact that Ubuntu's installer doesn't think RAID on the desktop is a thing. And, since it's been most of 4 years since I did the 16,04 install, I'd forgotten how I'd worked around this before. Turns out, it isn't terribly difficult. The basic thumbnail sketch is as follows: install mdadm in the live-boot environment; sudo mdadm --assemble --scan (to detect the existing RAID array); the installer will now happily detect the LVM volume groups and logical volumes; don't reboot yet! the installed system doesn't have mdadm yet and its initramfs needs rebuilding; so chroot to the installed rootfs with the various virtual filesystems mounted; apt install mdadm; put at least raid1 (I threw in lvm2 as well, but not sure that's required) in /etc/initramfs-tools/modules; update-initramfs; update-grub; exit chroot; okay, now reboot. If you forgot something, you can return to the live-boot'd thumbdrive and retry the chroot. Hope this helps someone, even if the someone is me in another 4 years. -- Russell Senior [email protected] _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
