Re: ZFS on Guix

[raid5atemyhomework]

> * the shepherd services defined in `configuration.scm`
>   seem one-shot services to me, so maybe add '(one-shot? #t)'.

I was wary of making the `zfs-scan` one-shot, since there is a dependent 
service on top of it.  Not to mention restarting `zfs-scan` could be useful if 
for example you were doing hotswapping of devices.  Maybe.


> * in the 'stop' of zfs-automount, the code changes the working
>   directory.  As it isn't restored afterwards, this doesn't seem
>   kosher to me.  Or maybe this isn't an issue at all.

The code is modeled after `file-system-shepherd-service` procedure in 
`gnu/services/base.scm`, which includes a `(chdir "/")` as well with the 
comment "Make sure PID 1 doesn't keep TARGET busy.".  Since this also does 
filesystem mounting/unmounting, I judged it best to imitate the existing 
filesystem mounting/unmounting service.

Thanks
raid5atemyhomework