thanks for a quick reply. For now, I will not go into patching the libguestfs by myself
since this is out of my scope. But I'm looking forward to see ZFS covered by this awesome
From: "Richard W.M. Jones" <rjones@redhat.com>
To: "Miha Pleško" <miha.plesko@xlab.si>
Cc: libguestfs@redhat.com
Sent: Thursday, October 12, 2017 11:49:11 AM
Subject: Re: [Libguestfs] ZFS Support
On Thu, Oct 12, 2017 at 09:46:13AM +0200, Miha Pleško wrote:
>
> Dear libguestfs developers,
>
> as explained yesterday by Ubuntu guys on my bug report
> https://bugs.launchpad.net/ubuntu/+source/libguestfs/+bug/1722800
>
> the libguestfs currently supports ZFS filesystem only partially
> i.e. for virt-rescue.
>
> Q: Would it be possible to bring ZFS support also to other
> libguestfs utils, like guestfish and virt-format?
>
> I would need to have two usecases supported:
Thanks for posting here. As you say, ZFS support in libguestfs is
currently very limited. Enabling it basically adds the userspace
package so it's available in virt-rescue, if you manually use the
‘zfs’/‘zpool’/etc commands.
> a) create a new volume with ZFS filesystem / format existing volume
> into ZFS filesystem
We could fairly easily make simple things work like creating a
filesystem. This is a good beginners patch as it just involves making
simple adjustments to this function:
https://github.com/libguestfs/libguestfs/blob/master/daemon/mkfs.c#L35
> b) manage files from ZFS volume (read, write)
I believe that mounting a ZFS volume should just work currently. If
not, you might need to make only simple adjustments to the mount API:
https://github.com/libguestfs/libguestfs/blob/master/daemon/mount.ml#L24
This should allow you to read and write files.
Providing full ZFS volume management is a quite a bit harder. It
would involve pulling in some of the zfs APIs and turning them into
libguestfs APIs. There is lots of documentation about how to add new
APIs here:
http://libguestfs.org/guestfs-hacking.1.html#extending-libguestfs
I would start by looking at how other APIs have been implemented.
Particularly relevant would be the LVM and btrfs APIs, eg:
https://github.com/libguestfs/libguestfs/blob/master/daemon/btrfs.c
Rich.
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