4:28 p.m.
Hi,
Here are the OpenVZ support patches. The .c and .h files go into src/
This is being released in the spirit of releasing early. Only the basic
stuff is done and development is continuing.
What works:
* Getting number of active/inactive domains
* Listing active/inactive domains
* Creating a domain that has been already defined (using OpenVZ tools)
* Shutdown, start, reboot
* configure.in has a new switch --with-openvz(on by default), use
--without-openvz to switch it off.
After I get feedback, I will work on it and add other features later on.
There is no need for any OpenVZ tools code. Just the OpenVZ kernel and
tools need to be installed. This code depends on the OpenVZ tool
binaries.
Differences from QEMU/Xen:
* ID and name are same
* Not possible to create temporary domains and do away with them.
Creating a domain will involve untarring a template cache and bringing
it up.
* No readonly access. OpenVZ tools need root access.
There are other design issues to be discussed. These issues spring from
the fact that OpenVZ is very different from Xen/QEMU. I will discuss
these issues in further mails.
Here is a sample session transcript:
shuveb@debian-openvz:~/libvirt$ sudo src/virsh -c openvz:///system
Welcome to lt-virsh, the virtualization interactive terminal.
Type: 'help' for help with commands
'quit' to quit
virsh # list
Id Name State
----------------------------------
101 101 running
102 102 running
103 103 running
virsh # shutdown 101
Domain 101 is being shutdown
virsh # list
Id Name State
----------------------------------
102 102 running
103 103 running
virsh # list --all
Id Name State
----------------------------------
102 102 running
103 103 running
- 101 shut off
virsh # start 101
Domain 101 started
virsh # list
Id Name State
----------------------------------
101 101 running
102 102 running
103 103 running
virsh #
Thanks and Regards,
--
Shuveb Hussain
Unix is very user friendly. It is just a
little choosy about who its friends are
http://www.binarykarma.com
8:09 a.m.
On Mon, Jul 16, 2007 at 01:58:41PM +0530, Shuveb Hussain wrote:
Hi,
Here are the OpenVZ support patches. The .c and .h files go into src/
This is being released in the spirit of releasing early. Only the basic
stuff is done and development is continuing.
What works:
* Getting number of active/inactive domains
* Listing active/inactive domains
* Creating a domain that has been already defined (using OpenVZ tools)
* Shutdown, start, reboot
* configure.in has a new switch --with-openvz(on by default), use
--without-openvz to switch it off.
After I get feedback, I will work on it and add other features later on.
There is no need for any OpenVZ tools code. Just the OpenVZ kernel and
tools need to be installed. This code depends on the OpenVZ tool
binaries.
Differences from QEMU/Xen:
* ID and name are same
So open VZ has no kind of unique identifier aside from its ID numbers ?
* Not possible to create temporary domains and do away with them.
Creating a domain will involve untarring a template cache and bringing
it up.
No problem.
* No readonly access. OpenVZ tools need root access.
Since your openvz driver is returning VIR_OPEN_DECLINED when run as
non-root, we can trivially make sure that the general purpose 'remote
driver' handles the non-root case. This would allow read-only acces
to the openvz driver by non-root - the tools would be run indirctly
by the libvirt daemon.
A couple of quick comments about the drivers thus far
- I'd prefer if we avoided the use of popen(). Since you know the exact
finite set of arguments needed for each invocation of the OpenVZ tools
I think it'd be preferrable to just pack them into a char **argv and
do plain fork/exec. This avoids the extra shell invocation, and any
unexpected security issues you might see by the shell globbing / or
interpreting the args in unexpected ways. The qemu_driver.c has a
function 'qemudExec' which takes a char **argv to run, and does the
fork/exec pair, returning you 2 file handles - one for stdout, and
the other for stderr.
This avoids the shell, and lets you easily separate the regular output
from the error output - with the shell you get stdout & stderr merged
into one making parsing potentially unreliable.
It might in fact be a good idea if we moved 'qemuExec' out into a
separate file so it can be shared/used by any/all drivers which need
to exec things.
- Take a look at the src/uuid.h file which has functions you can call
to parse & generate UUIDs - we just separated them out from QEMU to
allow re-use across drivers.
Overall the structure of the driver looks sane to me. I'll be interested to
here what thoughts you have wrt to XML because as you say container based
virt will have some interesting differences from hypervisor based virt in
this respect.
Regards,
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 -=|
1:59 p.m.
[...]
>
> Differences from QEMU/Xen:
>
> * ID and name are same
So open VZ has no kind of unique identifier aside from its ID numbers ?
Yeah, true.
> * Not possible to create temporary domains and do away with them.
> Creating a domain will involve untarring a template cache and bringing
> it up.
No problem.
> * No readonly access. OpenVZ tools need root access.
Since your openvz driver is returning VIR_OPEN_DECLINED when run as
non-root, we can trivially make sure that the general purpose 'remote
driver' handles the non-root case. This would allow read-only acces
to the openvz driver by non-root - the tools would be run indirctly
by the libvirt daemon.
Sure.
A couple of quick comments about the drivers thus far
- I'd prefer if we avoided the use of popen(). Since you know the exact
finite set of arguments needed for each invocation of the OpenVZ tools
I think it'd be preferrable to just pack them into a char **argv and
do plain fork/exec. This avoids the extra shell invocation, and any
unexpected security issues you might see by the shell globbing / or
interpreting the args in unexpected ways. The qemu_driver.c has a
function 'qemudExec' which takes a char **argv to run, and does the
fork/exec pair, returning you 2 file handles - one for stdout, and
the other for stderr.
This avoids the shell, and lets you easily separate the regular output
from the error output - with the shell you get stdout & stderr merged
into one making parsing potentially unreliable.
It might in fact be a good idea if we moved 'qemuExec' out into a
separate file so it can be shared/used by any/all drivers which need
to exec things.
I will work on this.
- Take a look at the src/uuid.h file which has functions you can call
to parse & generate UUIDs - we just separated them out from QEMU to
allow re-use across drivers.
I'll try to use these and remove any code with duplicate functionality.
Overall the structure of the driver looks sane to me. I'll be interested to
here what thoughts you have wrt to XML because as you say container based
virt will have some interesting differences from hypervisor based virt in
this respect.
Daniel, we had this discussion going a couple of months earlier on the
list. Sure, there are fundamental differences between Xen/QEMU VMs and
containers like OpenVZ and the current XML format may not be sufficient
for containers. I'll consolidate my concerns and mail the list back.
Thanks for the comments,
Regards,
--
Shuveb Hussain
Unix is very user friendly. It is just a
little choosy about who its friends are
http://www.binarykarma.com
7 p.m.
On Mon, Jul 16, 2007 at 01:58:41PM +0530, Shuveb Hussain wrote:
Hi,
Here are the OpenVZ support patches. The .c and .h files go into src/
This is being released in the spirit of releasing early. Only the basic
stuff is done and development is continuing.
What works:
* Getting number of active/inactive domains
* Listing active/inactive domains
* Creating a domain that has been already defined (using OpenVZ tools)
* Shutdown, start, reboot
* configure.in has a new switch --with-openvz(on by default), use
--without-openvz to switch it off.
After I get feedback, I will work on it and add other features later on.
There is no need for any OpenVZ tools code. Just the OpenVZ kernel and
tools need to be installed. This code depends on the OpenVZ tool
binaries.
Differences from QEMU/Xen:
* ID and name are same
* Not possible to create temporary domains and do away with them.
Creating a domain will involve untarring a template cache and bringing
it up.
* No readonly access. OpenVZ tools need root access.
There are other design issues to be discussed. These issues spring from
the fact that OpenVZ is very different from Xen/QEMU. I will discuss
these issues in further mails.
Here is a sample session transcript:
Okay, that works ! I have installed OpenVZ myself and applied the patches
locally. After renaming the readline in the openvz_conf.c to avoid overriding
the system one (and then crashing libvirt), it worked for me on x86_64.
There are slight differences in behaviour, for example shutdown looks
synchronous (but since it's very fast it's not that a big deal).
There is a lot of stuff I would like to change, for example make all
the module functions private, the readline renaming, etc ... What I would
suggest is the following:
- commit the new files to CVS
- apply the patch but make the openvz configure off by default
Then we can work out of CVS, which will make cooperative development easier.
If that's good for you tell me, I will arrange the commits etc,
thanks a lot !
Daniel
--
Red Hat Virtualization group http://redhat.com/virtualization/
Daniel Veillard | virtualization library http://libvirt.org/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
7:45 p.m.
On Tue, 2007-07-17 at 07:00 -0400, Daniel Veillard wrote:
Okay, that works ! I have installed OpenVZ myself and applied the
patches
locally. After renaming the readline in the openvz_conf.c to avoid overriding
the system one (and then crashing libvirt), it worked for me on x86_64.
There are slight differences in behaviour, for example shutdown looks
synchronous (but since it's very fast it's not that a big deal).
There is a lot of stuff I would like to change, for example make all
the module functions private, the readline renaming, etc ... What I would
suggest is the following:
- commit the new files to CVS
- apply the patch but make the openvz configure off by default
Then we can work out of CVS, which will make cooperative development easier.
If that's good for you tell me, I will arrange the commits etc,
Great! I will work on the feedback provided by you and Daniel. B. A
commit will help speedup generating patches a lot.
Thanks!
Regards,
--
Shuveb Hussain
Unix is very user friendly. It is just a
little choosy about who its friends are
http://www.binarykarma.com
9:28 p.m.
On Tue, Jul 17, 2007 at 05:15:19PM +0530, Shuveb Hussain wrote:
On Tue, 2007-07-17 at 07:00 -0400, Daniel Veillard wrote:
> Okay, that works ! I have installed OpenVZ myself and applied the patches
> locally. After renaming the readline in the openvz_conf.c to avoid overriding
> the system one (and then crashing libvirt), it worked for me on x86_64.
> There are slight differences in behaviour, for example shutdown looks
> synchronous (but since it's very fast it's not that a big deal).
> There is a lot of stuff I would like to change, for example make all
> the module functions private, the readline renaming, etc ... What I would
> suggest is the following:
> - commit the new files to CVS
> - apply the patch but make the openvz configure off by default
> Then we can work out of CVS, which will make cooperative development easier.
>
> If that's good for you tell me, I will arrange the commits etc,
Great! I will work on the feedback provided by you and Daniel. B. A
commit will help speedup generating patches a lot.
Okay, done, run cvs update you should get those,
thanks !
Daniel
--
Red Hat Virtualization group http://redhat.com/virtualization/
Daniel Veillard | virtualization library http://libvirt.org/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
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5 comments
3 participants
participants (3)
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Daniel P. Berrange -
Daniel Veillard -
Shuveb Hussain