Nathan,

You may well be the first to (try to) use bcache on Guix System.

Nathan Dehnel 写道：
> The manual https://www.kernel.org/doc/Documentation/bcache.txt 
> states
> that udev is necessary, and it is enabled:

It says:

--8<---------------cut here---------------start------------->8---
bcache-tools now ships udev rules, and bcache devices are known to
the kernel immediately.
--8<---------------cut here---------------end--------------->8---

which is a bit more than that.  Guix doesn't ship bcache-tools 
(yet); are you using your own package?  If so, please consider 
sharing :-)

You'd have to add it to the RULES field of your system's 
UDEV-CONFIGURATION to make the system's udev ‘see’ the rules. 
Simply installing it or adding it to your system packages isn't 
enough.

The kernel docs continue:

--8<---------------cut here---------------start------------->8---
Without udev, you can manually register devices like this::

  echo /dev/sdb > /sys/fs/bcache/register
  echo /dev/sdc > /sys/fs/bcache/register

Registering the backing device makes the bcache device show up in
/dev; you can now format it and use it as normal.
--8<---------------cut here---------------end--------------->8---

Have you tried this?

Good luck,

T G-R