04-11-2021, 08:40 AM
I have no experience with LVM managed storage, but with regular BIOS or GPT partitions you can specify that partitions be mounted without formatting. You need to use the "something else" (sorry, can't recall exact name of option) option at the partition stage. The other trick is to make sure you create users in the 5.x system with the same userids as the older system so that ownerships match up. The default "overwrite" partitioning option would only reformat the selected installation drive so if you selected one of the SSDs it wouldn't look at your LVM partitions (and they wouldn't be automatically assigned mount points either, though you could add them later by saving the /etc/fstab from the 4.8 installation and editing the partition details into your 5.4 /etc/fstab - just don't overwrite the 5.4 file with the 4.8 file!).
If it were me, I'd use the spare SSD for the 5.4 install as a dry run - just read up about grub and keep copies of the files on a USB drive so you can easily change back to the 4.8 install if needed. Once you're comfortable with the process, you can then redo the install onto the main SSD.
If it were me, I'd use the spare SSD for the 5.4 install as a dry run - just read up about grub and keep copies of the files on a USB drive so you can easily change back to the 4.8 install if needed. Once you're comfortable with the process, you can then redo the install onto the main SSD.