I hope you will bear with my learning curve...
I installed Zorin OS 18 with LVM, reading that it was a good flexible option. Now I'm doubting that it's the right choice for me, and I'd like some guidance.
As described in my previous post, I split my LVM 1TB SSD into a 200GB root drive and an 800GB data partition, thinking that I could back up & restore just the root partition quickly and easily. However, Rescuezilla sees only the entire 1TB - a 500MB partition and the full 1TB drive - and therefore includes all the data in the backup, the very thing I was trying to avoid.
So... am I misunderstanding? An article from 2020 says that Rescuezilla doesn't handle LVM well, so I may just be stuck.
If this is the case, would I be better off with a non-LVM drive? I.E. should I reinstall Zorin with "standard" partitioning, and use Gparted to split the SSD? Would that give me the Rescuezilla backup separation that I want?
And if this is the case, can I use a pre-repartition Rescuezilla backup to restore my system to the new non-LVM installation, or would that image contain the LVM settings and refuse to restore or work, in which case I would have to reinstall Zorin from scratch?
Thank you for your help and patience...
LVM is beneficial if you need to expand partitions but if you are happy with the sizes you created, then don't use LVM. I would backup your Data first, then reinstall. Alternatively, just install Timeshift which is a system restore utility that focuses on the system and excludes /home by default. Be aware that this is a snapshot utility, not a backup one. I use the /home partition to store the snapshots and reduce the default setting of 5 snapshots a day to 3. I should also add I don't use SSD. Lastly Timeshift only works with Ext4 FS, not BTRFS etc.
Thanks, Swarfendor. Until I need to install from scratch, I'll leave things as they are. I've enabled Timeshift, so I'll see how it goes. Even omitting Home & Root, I was amazed to see 700k files being copied... There's more going on behind the scenes than we mere mortals can imagine... 
With an LVM default install, you don't have a root partition, you have a root logical volume. That's very different.
Rescuezilla is a backup imaging tool? It may only work on entire partitions. I backup LVM logical volumes by just copying the files elsewhere.
Thanks again, Topaz. I'll get there eventually...
I have used Rescuezilla already to back up and restore my system (before I split my SSD), and it worked fine. I had already emptied the SSD by moving all my data to an external disk, so the backup was small (about 30GB), whereas this time with my data on the 800GB data volume Rescuezilla was including it as part of an entire disk backup, as you say, not ignoring the data volume as I had hoped.
@swarfendor437: I've just rebooted my laptop and found a blank desktop, all icons disappeared. After a bit of thought and googling, I remembered your Timeshift advice, and I'm back to normal again inside 5 minutes. Thank you again for the pointer.