I'm planning on doing a migration of my Debian installation from one disk to another in the near future. As a part of that, I'm thinking about setting the file systems up differently, for future-proofing as well as for simplifying the setup.
My current setup is a one-device RAID1 LVM (I originally intended to set up mirroring of the system disk, but never got around to actually doing that) on a partition on a SSD. That RAID1 in turn holds the ext4 root file system, with /opt plus parts of /usr and /var separated onto ZFS storage. Particularly, /boot is part of the root file system, and I'm booting using old-style MBR using GRUB 2.
The idea is to have a large root file system with a *nix-esque file system (probably ext4 to begin with), and to separate out the parts that have special needs.
I'd like to leave open the possibility of migrating to UEFI boot later, possibly including a migration to GPT, without needing to move things around. (Backup/repartition/restore is another matter, and will likely be needed for migrating from MBR to GPT, but I'll probably be getting a new disk again before that becomes an issue.)
I'd also like to have the option to migrate the root file system to ZFS later, or at least to set up dm-verity for data integrity verification. (Yes, it'll be a bit of a headache to get everything about that right, especially semi-in-place. That'll be a matter for a later day; their only consideration for this question is in terms of later options.)
This all seems to make an obvious case for separating
/boot and the FAT32
/boot/efi (the last of which may initially be empty), in addition to those that I have already separated from the root file system. But are there others?
- Which system file systems, backed by persistent storage, should be separated from the root file system and why on a modern-day Linux installation?
- Do any of these file systems need to go onto specific partition locations when using MBR, or are their locations arbitrary? For example, would /boot/efi need to go onto the first primary partition or something like that?