[bug#47905] gnu: Add rasdaemon.

[Leo Famulari]

On Tue, Apr 20, 2021 at 01:24:37PM +0900, elaexuotee--- via Guix-patches via 
wrote:
> * doc/guix.texi (Linux Services): Document it.

It could be added to Monitoring Services instead. Although, RAS is
Linux-only, so I leave that decision up to you.

> +@cindex rasdaemon
> +@cindex Platform Reliability, Availability and Serviceability daemon
> +@subsubheading Rasdaemon Service
> +
> +The Rasdaemon service provides a monitor for Platform Reliability,
> +Availability, and Serviceability (RAS) events in the Linux kernel.

It would be nice to link to some upstream documentation of RAS, as we do
for the documentation of the Zram Device Service.

I think it could also be improved with addition of one or two sentences
about how to make use of the service. As logging appears to be disabled
by default, how are users expected to learn of the events monitored by
rasdaemon?

After writing that, I looked at rasdaemon-shepherd-service and see that
it keeps a log file. Is that the same data as the optional SQLite
database, but unstructured?

Overall, the docs should clarify this :)