1:36 p.m.
NOTE: This is HIGHLY EXPERIMENTAL and can eat babies ...
Modify the guest libvirt XML to add the virtio-serial channel:
<channel type='unix'>
<source mode='bind' path='/tmp/socket'/>
<target type='virtio' name='org.libguestfs.channel.0'/>
</channel>
In the guest, compile guestfsd and run it like this:
sudo daemon/guestfsd -rv
(XXX - should current directory be / ...?)
In the host connect using:
sudo guestfish -d GuestName --live
<fs> run
<fs> ll /
etc.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine. Supports Linux and Windows.
http://et.redhat.com/~rjones/virt-df/
1:36 p.m.
New subject: [PATCH 1/8 v2 DISCUSSION ONLY] Move appliance launching to separate function.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
New in Fedora 11: Fedora Windows cross-compiler. Compile Windows
programs, test, and build Windows installers. Over 70 libraries supprt'd
http://fedoraproject.org/wiki/MinGW http://www.annexia.org/fedora_mingw
1:37 p.m.
New subject: [PATCH 2/8 v2 DISCUSSION ONLY] New APIs: set-attach-method, get-attach-method.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines. Supports shell scripting,
bindings from many languages. http://libguestfs.org
1:37 p.m.
New subject: [PATCH 3/8 v2 DISCUSSION ONLY] lib: Implement attach-method unix:<path>
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-top is 'top' for virtual machines. Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://et.redhat.com/~rjones/virt-top
1:37 p.m.
New subject: [PATCH 4/8 v2 DISCUSSION ONLY] daemon: Allow -r option to run daemon standalone.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming blog: http://rwmj.wordpress.com
Fedora now supports 80 OCaml packages (the OPEN alternative to F#)
http://cocan.org/getting_started_with_ocaml_on_red_hat_and_fedora
1:38 p.m.
New subject: [PATCH 5/8 v2 DISCUSSION ONLY] daemon: Remove -f (don't fork) option.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
New in Fedora 11: Fedora Windows cross-compiler. Compile Windows
programs, test, and build Windows installers. Over 70 libraries supprt'd
http://fedoraproject.org/wiki/MinGW http://www.annexia.org/fedora_mingw
1:38 p.m.
New subject: [PATCH 6/8 v2 DISCUSSION ONLY] Add guestfs_add_domain 'live' flag.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming blog: http://rwmj.wordpress.com
Fedora now supports 80 OCaml packages (the OPEN alternative to F#)
http://cocan.org/getting_started_with_ocaml_on_red_hat_and_fedora
1:38 p.m.
New subject: [PATCH 7/8 v2 DISCUSSION ONLY] Add documentation for attach method.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
New in Fedora 11: Fedora Windows cross-compiler. Compile Windows
programs, test, and build Windows installers. Over 70 libraries supprt'd
http://fedoraproject.org/wiki/MinGW http://www.annexia.org/fedora_mingw
1:39 p.m.
New subject: [PATCH 8/8 v2 DISCUSSION ONLY] fish: Add guestfish --live, guestmount --live options.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-top is 'top' for virtual machines. Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://et.redhat.com/~rjones/virt-top
9:15 a.m.
New subject: [PATCH 8/8 v2 DISCUSSION ONLY] fish: Add guestfish --live, guestmount --live options.
On Fri, Jan 28, 2011 at 07:39:09PM +0000, Richard W.M. Jones wrote:
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-top is 'top' for virtual machines. Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://et.redhat.com/~rjones/virt-top
>From 4891a885aa7058faba901c059f08ddfbc5d43159 Mon Sep 17 00:00:00
2001
From: Richard W.M. Jones <rjones(a)redhat.com>
Date: Fri, 28 Jan 2011 19:25:02 +0000
Subject: [PATCH 8/8] fish: Add guestfish --live, guestmount --live options.
The other programs have the variable, but the flag is not enabled
either because it doesn't make sense or because the implications are
not well understood.
---
cat/virt-cat.c | 2 ++
cat/virt-filesystems.c | 2 ++
cat/virt-ls.c | 2 ++
df/main.c | 2 ++
I would have thought it was ok to support --live in
these 4, since they're readonly apps in any case.
fish/fish.c | 5 +++++
fish/guestfish.pod | 5 +++++
fish/inspect.c | 6 ++++++
fish/options.h | 1 +
fish/virt.c | 4 ++++
fuse/guestmount.c | 5 +++++
fuse/guestmount.pod | 5 +++++
inspector/virt-inspector.c | 2 ++
rescue/virt-rescue.c | 2 ++
--live probably isn't useful for virt-rescue since if
you need to rescue a machine it likely isn't running
correctly & thus not have a guestfsd available.
Daniel
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
11:24 a.m.
New subject: [PATCH 8/8 v2 DISCUSSION ONLY] fish: Add guestfish --live, guestmount --live options.
On Thu, Feb 03, 2011 at 03:15:08PM +0000, Daniel P. Berrange wrote:
On Fri, Jan 28, 2011 at 07:39:09PM +0000, Richard W.M. Jones wrote:
[...]
Thanks for reviewing these. I'm trying to get something I can push
(even partial) before I go on holiday.
> >From 4891a885aa7058faba901c059f08ddfbc5d43159 Mon Sep 17
00:00:00 2001
> From: Richard W.M. Jones <rjones(a)redhat.com>
> Date: Fri, 28 Jan 2011 19:25:02 +0000
> Subject: [PATCH 8/8] fish: Add guestfish --live, guestmount --live options.
>
> The other programs have the variable, but the flag is not enabled
> either because it doesn't make sense or because the implications are
> not well understood.
> ---
> cat/virt-cat.c | 2 ++
> cat/virt-filesystems.c | 2 ++
> cat/virt-ls.c | 2 ++
> df/main.c | 2 ++
I would have thought it was ok to support --live in
these 4, since they're readonly apps in any case.
That argument is an argument _against_ doing it :-)
Currently there is nothing special about --ro in the protocol. What
happens is that we add the drives using 'add-drive-ro' which uses
qemu's snapshot facility to unwind any writes: an anonymous snapshot
is mounted over each drive, writes are permitted, but they only update
the snapshot which is discarded at the end.
Thus you can use --ro / 'add_drive_ro' and your program can write
merrily away, safe in the knowledge that writes are being discarded by
qemu. Your program can even read back the results of its writes. In
fact in virt-resize we deliberately write to read-only drives.
The point anyway is the protocol itself does not have a "read only
mode" or any understanding of which operations are read-only vs write.
Some operations which seem like they must be read-only
(eg. 'mount-ro') can write to the disk. The anonymous snapshot is
what saves us from having 'mount-ro' modify the superblock last mount
times, replay the journal, etc.
In the case of a live guest, we are able to write and there is no
snapshotting to unwind any changes we make.
'virt-cat', 'virt-df' and others almost certainly will make
unintentional changes to live guests (definitely mounting and
unmounting filesystems), and thus it is not safe to use them until we
have very carefully inspected the code and/or they are modified to
behave properly when run on a live guest.
> fish/fish.c | 5 +++++
> fish/guestfish.pod | 5 +++++
> fish/inspect.c | 6 ++++++
> fish/options.h | 1 +
> fish/virt.c | 4 ++++
> fuse/guestmount.c | 5 +++++
> fuse/guestmount.pod | 5 +++++
> inspector/virt-inspector.c | 2 ++
> rescue/virt-rescue.c | 2 ++
--live probably isn't useful for virt-rescue since if
you need to rescue a machine it likely isn't running
correctly & thus not have a guestfsd available.
Agreed. Because of "direct mode"[1] it's not likely virt-rescue could
ever have a --live option. Use ssh :-)
Rich.
[1] http://libguestfs.org/guestfs.3.html#guestfs_set_direct
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming blog: http://rwmj.wordpress.com
Fedora now supports 80 OCaml packages (the OPEN alternative to F#)
http://cocan.org/getting_started_with_ocaml_on_red_hat_and_fedora
9:17 a.m.
On Fri, Jan 28, 2011 at 07:36:34PM +0000, Richard W.M. Jones wrote:
NOTE: This is HIGHLY EXPERIMENTAL and can eat babies ...
Modify the guest libvirt XML to add the virtio-serial channel:
<channel type='unix'>
<source mode='bind' path='/tmp/socket'/>
<target type='virtio' name='org.libguestfs.channel.0'/>
</channel>
In the guest, compile guestfsd and run it like this:
sudo daemon/guestfsd -rv
(XXX - should current directory be / ...?)
Yeah, I think it makes sense to have it chdir(/) so that
it doesn't accidentally cause a random FS to remain busy.
In the host connect using:
sudo guestfish -d GuestName --live
><fs> run
><fs> ll /
etc.
I think this series all looks fine. Obviously the main implication you
mentioned before is that we'll need to be strict about the RPC wire
back-compat support from this point forward.
Also need a init script (or systemd unit) to start the guestfsd if-only-if
it sees the virtio socket present inside the guest.
Regards,
Daniel
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
11:29 a.m.
On Thu, Feb 03, 2011 at 03:17:39PM +0000, Daniel P. Berrange wrote:
I think this series all looks fine. Obviously the main implication
you
mentioned before is that we'll need to be strict about the RPC wire
back-compat support from this point forward.
Indeed .. I need to go back over the protocol and features to make
sure there's no immediate feature we need which would require a change
in the protocol. In any case, nothing would be binding until 1.10 is
released.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines. Supports shell scripting,
bindings from many languages. http://libguestfs.org
12:55 p.m.
I have PUSHED these patches to the repository.
Note that these could eat babies, so please treat with caution. You
might want to roll back to the 1.9.7 tag if you want something more
stable.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines. Boot with a
live CD or over the network (PXE) and turn machines into Xen guests.
http://et.redhat.com/~rjones/virt-p2v
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