I installed Asahi Linux to a 128 GB rootfs (out of 1 TB of internal storage). It is connected to a dock with an external 1 TB M.2 drive. Fedora sees this drive as /dev/sda.

Migrating the subvolume of /home was just a matter of creating a single all encompassing BTRFS partition to /dev/sda and then:

sudo btrfs device add /dev/sda1 /home -f
sudo btrfs device remove /dev/nvme0n1p6 /home -f

Now there is an airtight separation / and /home physically, and also they pool space only within their own cages.

Apple firmware supports only booting macOS from external storage, thus the rootfs must always reside in the internal storage, but I think this is already quite sustainable way to deal with it.

This bottleneck/policy can be mitigated but it does not pay the price. It can be overcome by installing macOS to an external storage and consuming internal storage in its full extent for Asahi Linux. Just mentioning this last for completeness ;-)

Encryption can/could be done by following https://davidalger.com/posts/fedora-asahi-remix-on-apple-silicon-with-luks-encryption/ with “a twist’ (since different partition/drive topology).

#apple #macos #linux #asahilinux

The end result:

$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1       932G   14G  918G   2% /
vendorfw         16G   79M   16G   1% /usr/lib/firmware/vendor
devtmpfs        4.0M     0  4.0M   0% /dev
tmpfs            16G     0   16G   0% /dev/shm
tmpfs           6.3G   22M  6.2G   1% /run
tmpfs            16G   18M   16G   1% /tmp
/dev/nvme0n1p5  974M  234M  673M  26% /boot
/dev/sda1       932G   14G  918G   2% /home
/dev/nvme0n1p4  499M  129M  371M  26% /boot/efi
tmpfs           3.2G  864K  3.2G   1% /run/user/1000

$ sudo btrfs filesystem show  
Label: 'fedora'  uuid: ff4c6159-93b4-49db-b9fe-13fdb502563c
	Total devices 1 FS bytes used 12.33GiB
	devid    2 size 931.51GiB used 20.06GiB path /dev/sda1