I'm converting an older system from Debian to guix. I've got it all set
up with brand new large spinning disks and some SSD partitions to act as
bcache cache devices.
When the system boots the bcache devices aren't recognized. If I run
bcache show
I can get a list of devices
and if I run
bcache register X
on all the devices X listed in the list... I can get /dev/mapper/bcache0
and /dev/mapper/bcache1 where my filesystems reside.
Rather than doing this manually on every boot, I'd like guix to register
the devices during boot, maybe by including a
bcache-registration-service-type in my services?
The actual code to use open-pipe* to run bcache and accomplish the stuff
isn't too hard in guile but the part I don't understand is how to hook
this registration process into the boot process so that the machine can
just come up with bcache devices registered and the relevant fs mounted?
I'm happy to write the necessary code and submit it as a PR, but I need
help understanding how guix boots and how the shepherd works enough to
figure out how to hook into the boot process.
Can someone describe at high level, the "right way" to get shepherd to
call my scheme functions to register the bcaches?
