On Thu, Jun 14, 2007 at 05:55:33PM +0200, Jim Meyering wrote:
"Richard W.M. Jones" <rjones@redhat.com> wrote: ...
From the virt-manager/libvirt p.o.v. it seems to me the important operations are:
(1) Find attached drives.
(2) Find partitions available & their sizes.
(3) Allocate logical volumes.
(4) Find out how much free space is available on a partition, and carve out a file.
How about creating a regular partition, or resizing an existing (non-LVM) file system?
Correct me if I'm wrong (I usually am), but:
Nothing can do (1) except doing a brute force scan over /dev and looking for likely block devices (this is what vgscan does).
Parted can do (2), with several limitations including sector size. It can't do (3) at all, but then neither can anything else except forking the LVM command line tools.
And (4) can be done by libvirtd using ordinary POSIX calls, so no external library support is needed, just some work to remote those operations (which is mostly done).
Isn't doing #4 portably pretty tricky? There's still too much variation, because many of the details aren't covered by POSIX. At least for GNU df, it was -- it uses the mountlist module from gnulib:
We don't need to enumerate all the mount points. The admin will simply configure particulra directories (eg /var/lib/xen/images) as storage repositories. So we only need to be able to call statfs/statvfs on particular paths where we want to create a new image.
Of course, if your target is just Linux, then it is easier.
Minimally we have to target Solaris too, since we know they already use libvirt. Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|