> In a traditional "full" installation, the filesystem occupies an entire partition, with the usual /etc, /bin, /usr, /proc, /sys, /tmp, etc. Easy does not install like this.
> Easy installs to hard drive in what we call frugal
mode, which occupies just one folder in a partition, allowing to co-exist with whatever else the partition is used for.
Honestly, this is huge. I wish all distros supported this out of the box. It would be a lot less daunting to reinstall your system or try out a new distro if you could preserve your current working system in another directory.
With a gparted liveCD and a big enough spare disk / USB drive you can move unmounted partitions around to your liking. If your filesystem supports shrinking then you may not even need a spare disk. And have a phone or another computer that you can use to read man pages, ArchWiki, etc for help.
Practice in a VM if you need to.
I once moved a system that had one unencrypted partition for everything and booted in BIOS mode, to two encrypted partitions for `/` and `/home` that booted in UEFI mode, all from a gparted live CD plus a live CD of the actual distro I use (useful for chrooting to be sure I was using the same kernel and filesystem packages, and because I needed to update the packages and configs in `/` itself). Didn't lose any data or need to do any backup-restores. Just do everything carefully, one step at a time.
> I once moved a system that had one unencrypted partition for everything and booted in BIOS mode, to two encrypted partitions for `/` and `/home` that booted in UEFI mode [...]
I've done this a bunch of times. First from a single partition on a spinning disk 7 years ago to slowly migrating more and more parts onto SSD's as they became affordable, then converting the root to GPT, and finally merging it all back when I finally had an SSD big enough to store all of it. You just make your new partitions and rsync it all on there. The most important part is keeping all of the file attributes, but the correct rsync flags take care of that. Then you just need to update your fstab and bootloader and you're basically golden. It's been quite simple.
The key for me has been to keep the old stuff in place for a first boot so that I could easily recover if I fucked it up. I've never needed it, but it was a nice feeling of safety.
btrfs already supports this using subvolumes but you have to install the OSes manually (no installer supports this OOTB afaik)
however Fedora uses btrfs with two subvolumes (root and home) by default but I haven't found a way to install it without formatting the root filesystem though.
> In a traditional "full" installation, the filesystem occupies an entire partition, with the usual /etc, /bin, /usr, /proc, /sys, /tmp, etc. Easy does not install like this.
> Easy installs to hard drive in what we call frugal mode, which occupies just one folder in a partition, allowing to co-exist with whatever else the partition is used for.
Honestly, this is huge. I wish all distros supported this out of the box. It would be a lot less daunting to reinstall your system or try out a new distro if you could preserve your current working system in another directory.