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. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top