My PC has a 120 GB SSD and a 2 TB HDD. i want to cache the HDD with the SSD with bcache. I think I would need a separate partition for /boot, /boot/efi and swap on the SSD. the rest of the SSD should cache the whole HDD. On the resulting bcache-device I want one large btrfs filesystem with /home and other as a separate subvolumes. I did not see an option for that in the Tumbleweed installer the last time I tried.
How can I do that? I am not afraid to invest time here initially but after that it should just work. I hope you can help me and I thank you in advance!
If so, I would look at booting from a live TW rescue USB and create the cache and edit the system fstab as required (never done this).
So what is the end game for bcache, is there a particular part of the filesystem your wanting to increase performance, eg kvm image partition, database etc?
You only need /boot/efi no separate /boot, swap and /.
You need bootloader that can read bcache or you need to maintain your kernel on ESP. I am not aware of openSUSE officially supporting systemd-boot and grub2 does not support bcache so /boot should leave outside of it, otherwise you will need to maintain your kernels in bootloader manually.
I gave up on it. I now habe a root partition in the SSD and my /home HDD is bcached with another portion oft the SSD.
I think this is the easy way, that makes the least trouble.