Re: mounting NTFS read-write

[ludo@gnu.org (Ludovic Courtès)]

Hi Marco,

Marco van Hulten <marco@hulten.org> skribis:

> I have this in my Guix configuration:
>
>     (file-system
>       (device "my-scratch")
>       (title 'label)
>       (mount-point "/scratch")
>       (type "ntfs")
>       (flags '(read-write user)))
>
> There are two problems with it.
>
> 1. The file system with label 'my-scratch' is not found.  Of course, I
> can use (device "/dev/sda6") instead.  But why can it not use the
> label?  It does turn up in cfdisk(8), just like for the root file
> system /dev/sda1.

The code in (gnu build file-systems) currently supports labels for
ext2/3/4, Btrfs, LUKS, FAT, and ISO9660.  It does not support NTFS.

Two options:

  1. Implement the missing bits in (gnu build file-systems).  :-)
     It’s really not that hard, there are examples you can use as a
     starting point.

  2. Stick to /dev/foo.

> 2. The flags are ignored.  At least the first one, read-write, is
> likely ignored because Linux does not support write access to NTFS
> file systems.  Then I looked in the manual [1], and found out that the
> flags read-write and user do not exist.  The former is maybe redundant
> because it is default (in case there is support for writable mount of
> the respective filesystem!), but the second could be useful, at least
> for removable media (though for that might exist other solutions).

OK.

I think ‘file-system’ declarations don’t work with FUSE file systems,
though.  Currently we just call mount(2) with the given system type,
whereas for NTFS it would need to invoke the mount.ntfs-3g program.

This is what would need to be fixed.

> Instead, NTFS file systems can be mounted with write access through
> fuse, using ntfs-3g.  So I installed ntfs-3g, and added a cron job to
> my /etc/config.scm; excerpt here:
>
>
> (use-modules (gnu services mcron))
> ...
> (define mount-ntfs-job
>   #~(job "@reboot"
>          "/root/.guix-profile/sbin/mount.ntfs-3g -o
>          rw /dev/sda6 /scratch"))

You could follow the Findutils example in
<https://www.gnu.org/software/guix/manual/html_node/Scheduled-Job-Execution.html>
instead of use /root/.guix-profile.

However I don’t think “@reboot” is supposed by mcron.

HTH,
Ludo’.