2011/6/13 <libvirt-users-request@redhat.com>

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Today's Topics:

1. Re: libvirt-bin MOSTLY fails to create default virtual
network (Laine Stump)
2. Boot delay (Jeff)
3. e: How to disconnect the ISO image using virsh (Jeff)
4. Difference between function Migrate and Migrate2 (Abhishek Gupta)
5. Re: Boot delay (Michal Privoznik)
6. hook scripts - not in Ubuntu packages? (Whit Blauvelt)

----------------------------------------------------------------------

Message: 1
Date: Sun, 12 Jun 2011 12:03:17 -0400
From: Laine Stump <laine@laine.org>
To: libvirt-users@redhat.com
Subject: Re: [libvirt-users] libvirt-bin MOSTLY fails to create
default virtual network
Message-ID: <4DF4E345.7060104@laine.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

On 06/06/2011 03:24 PM, m m wrote:
> I have observed 3 scenarios after I reboot the host with 2 guests
> (which are supposed to autostart after boot/reboot of the host):
> 1. Default network is created but I can not ping guests. Gests don't
> have assigned IP address or they both have IP address 192.168.122.100.
> 2. Default network is not created.
> 3. Default netork is properly created and everything works fine.
> In each case guests are started and they work properly. Cases 1. and
> 2. happen a lot more often then case 3.
>
> My solutions:
> - When I restart libvirt-bin then everything is fine.
> - When I set 'sleep 40' in 'pre-start' section of
> /etc/init/libvirt-bin.conf and modify 'start on' section in the
> following way:
>
> start on (runlevel [2345] and net-device-up IFACE=br0)
>
> then everything works fine.
>
>
> However, none of the above solutions indeed solves the problem.
> Please, let me know if there is solution to this problem or what are
> your suggestions regarding this issue.
>
> ****
> HOST$ uname -a
> Linux ras 2.6.32-32-server #62-Ubuntu SMP Wed Apr 20 22:07:43 UTC 2011
> x86_64 GNU/Linux
>
> GUEST1 and GUEST2
> $ uname -a
> Linux server1-desktop 2.6.32-32-generic #62-Ubuntu SMP Wed Apr 20
> 21:54:21 UTC 2011 i686 GNU/Linux
>
> HOST$ libvirtd --version
> libvirtd (libvirt) 0.7.5
>
> My idea was that some kernel modules sometimes are loaded before
> libvirt-bin starts, and sometimes libvirt-bin starts earlier, or in
> the middle of loading of these modules, that is why 3 scenarios can be
> observed.
> That is why I have added:
> cp /proc/modules /home/wsadmin2/modules1
> cp /proc/modules /home/wsadmin2/modules2
> to 'pre-start' and 'post-start' parts respectively of
> /etc/init/libvirt-bin.conf.
>
> Of course, beween execution of
> - pre-start part
> - exec /usr/sbin/libvirtd -d
> - post-start part
> other kernel modules can be loaded, so we can not be sure which
> additional modules in file 'modules2' were indeed loaded before
> libvirtd was actually started.
>
> Here are my observations:
> Scenatio 1.
> 33 (fixed) modules were logged - call them BASE MODULES.
>
> Scenatio 2.
> Beside BASE MODULES + the following modules were loaded:
>
> > iptable_filter 1841 0 - Live 0xffffffffa007c000
> > ip_tables 18201 1 iptable_filter, Live 0xffffffffa0172000
> > x_tables 22361 1 ip_tables, Live 0xffffffffa0164000

In your "scenario 1" the modules necessary for iptables to function
haven't been loaded. Each virtual network requires a set of iptables
rules to function properly, and if there is no iptables, the rules can't
be added and network creation fails. Your libvirtd.log confirms that
problem:

10:06:06.980: error : networkAddIptablesRules:750 : failed to add
iptables rule to allow DHCP requests from 'virbr0': Invalid argument

0.7.5 is quite old (> 1 year), is there perhaps a newer pre-built
version of libvirt available for your release of Ubuntu?

It seems that Ubuntu's method of starting up libvirtd (at least on your
machine) is missing a dependency to force iptables to be loaded before
libvirtd starts. I'm unfamiliar with Ubuntu/debian startup stuff
(upstart, I guess), but that's where you need to look for the solution.

I found the following in the ubuntu bug database, which seems similar,
but not identical (basically the system networking isn't completely
ready by the time the autostart domains are brought up):

https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/495394

>
> Scenatio 3.
> Beside BASE MODULES + the following modules were loaded:
>
> $ diff modules1 modules2
> 1c1,6
> < iptable_filter 1841 0 - Live 0xffffffffa008b000
> ---
> > xt_state 1490 14 - Live 0xffffffffa01ab000
> > xt_tcpudp 2667 12 - Live 0xffffffffa01a5000
> > nf_conntrack_ipv4 12742 14 - Live 0xffffffffa019b000
> > nf_conntrack 73326 2 xt_state,nf_conntrack_ipv4, Live 0xffffffffa017d000

conntrack is used by iptables. I haven't tried it, but wouldn't be
surprised if adding rules that required conntrack failed if it hadn't
been loaded, or something like that.

> > nf_defrag_ipv4 1481 1 nf_conntrack_ipv4, Live 0xffffffffa0177000
> > iptable_filter 1841 1 - Live 0xffffffffa008b000
> 3c8
> < x_tables 22361 1 ip_tables, Live 0xffffffffa0162000
> ---
> > x_tables 22361 3 xt_state,xt_tcpudp,ip_tables, Live 0xffffffffa0162000
>
> Other observations:
> Scenatio 1.
> No errors in libvirtd.log
> Scenario 2.
>
> 10:06:06.980: error : networkAddIptablesRules:750 : failed to add
> iptables rule to allow DHCP requests from 'virbr0': Invalid argument
> (...)
> 10:06:08.630: error : qemudNetworkIfaceConnect:1445 : Failed to add
> tap interface to bridge 'virbr0': No such device
> 10:06:08.630: error : qemuAutostartDomain:584 : Failed to autostart VM
> 'cluster_server1': Failed to add tap interface to bridge 'virbr0': No
> such device
>
> 10:06:08.921: info : qemudDispatchSignalEvent:390 : Received
> unexpected signal 17
> 10:06:08.927: debug : virExecWithHook:617 : LC_ALL=C /usr/bin/kvm -help
> 10:06:08.938: info : qemudDispatchSignalEvent:390 : Received
> unexpected signal 17
> 10:06:09.000: error : qemudNetworkIfaceConnect:1445 : Failed to add
> tap interface to bridge 'virbr0': No such device
> 10:06:09.000: error : qemuAutostartDomain:584 : Failed to autostart VM
> 'cluster_server2': Failed to add tap interface to bridge 'virbr0': No
> such device
> (...)
> Scenatio 3.
> No errors in libvirtd.log
>
>
> I didn't see any valuable logs in /var/log/boot.log,
> /var/log/messages, /var/log/syslog. Please let me know if you want to
> see them anyway or have any suggestions right away.
>
>
> _______________________________________________
> libvirt-users mailing list
> libvirt-users@redhat.com
> https://www.redhat.com/mailman/listinfo/libvirt-users

------------------------------

Message: 2
Date: Mon, 13 Jun 2011 08:25:00 -0500
From: Jeff <jwk1230@gmail.com>
To: libvirt-users@redhat.com
Subject: [libvirt-users] Boot delay
Message-ID: <4609858C-FB73-4E8A-B81B-3EDCBB83B755@gmail.com>
Content-Type: text/plain; charset=us-ascii

Is there a method of tweaking the boot sequence of a KVM instance so that you can delay the process for X number of seconds? I don't have enough time between starting the KVM and connecting via VNC.

Thanks

Jeff

------------------------------

Message: 3
Date: Fri, 10 Jun 2011 15:12:36 -0500
From: Jeff <jwk1230@gmail.com>
To: Osier Yang <jyang@redhat.com>, libvirt-users@redhat.com
Subject: [libvirt-users] e: How to disconnect the ISO image using
virsh
Message-ID: <F301FBCE-65F1-411A-980E-EF8B6A46241B@gmail.com>
Content-Type: text/plain; charset="utf-8"

I am trying to detach an ISO from a KVM machine and I've tried both attach-disk using " " in the file path as well as the update-device option but am getting this error

error: Failed to update device from /var/run/libvirt/qemu/kvmtest1.xml
error: XML description for unknown device type is not well formed or invalid.

I tried doing a virsh edit on the xml file to remove the source file path to the ISO, as I assume is the correct method, and then running the virsh update-device but it's not working.

Can anyone advise the correct steps to detach a device from a running and/or offline domain?

Additionally - anyone have any guidance on how to attach a CD device to a domain that is currently shutdown, for example, if I wanted to boot the domain to a rescue CD image?

Thanks

Jeff

? 2011?03?31? 15:17, Masanari Iida ??:
Somebody sent me a tips.
Following command do what I wanted to do.
Thanks.

attach-disk guest01 " " hdc --driver file --type cdrom
--mode readonly
Also using "update-device" with an xml which doesn't specify
the source file path will work.

On Thu, Mar 31, 2011 at 3:29 PM, Masanari Iida<standby24x7 gmail com> wrote:
Hello,

I can attach disc ISO image to cd-rom from virsh.
And I can replace the ISO image from disc1 to disc2 using the 2nd example.

(example)
attach-disk guest01 /root/disc1.iso hdc --driver file --type cdrom
--mode readonly
attach-disk guest01 /root/disc2.iso hdc --driver file --type cdrom
--mode readonly

My question is, how can I disconnect the image from the cdrom drive using virsh.
Because, if I try to detach-disk hdc, I got following errors.

virsh # detach-disk guest01 hdc
error: Failed to detach disk
error: this function is not supported by the connection driver:
This type of device cannot be hot unplugged

What I can do is possible from virt-manager's "Disconnect" button,
(next to source path: line) from Hardware's TAB, Disk hdc screen.
I want to do this from virsh.

OS: RHEL5.6
libvirt-0.8.2-15.el5_6.1 is used.

Regards,
Masanari Iida

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Message: 4
Date: Sat, 11 Jun 2011 06:39:46 +0530
From: Abhishek Gupta <cs1090174@cse.iitd.ernet.in>
To: libvirt-users@redhat.com
Subject: [libvirt-users] Difference between function Migrate and
Migrate2
Message-ID: <BANLkTinv6XiRMz=rS88A-U-b2Hz3SVTesg@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

I was reading the API reference for the libvirt, when I came across
the function? virDomainMigrate and virDomainMigrate2. I am unable to
find the difference between the two. Can someone please tell the
difference in the application of the two?

--
Abhishek

------------------------------

Message: 5
Date: Mon, 13 Jun 2011 17:21:02 +0200
From: Michal Privoznik <mprivozn@redhat.com>
To: Jeff <jwk1230@gmail.com>
Cc: libvirt-users@redhat.com
Subject: Re: [libvirt-users] Boot delay
Message-ID: <4DF62ADE.60209@redhat.com>
Content-Type: text/plain; charset=ISO-8859-1

On 13.06.2011 15:25, Jeff wrote:
> Is there a method of tweaking the boot sequence of a KVM instance so that you can delay the process for X number of seconds? I don't have enough time between starting the KVM and connecting via VNC.
>
You might consider using virt-viewer. It simply waits for domain to
boot, if it is down.

Your other option is to create hook script:
http://libvirt.org/hooks.html
and put conditional sleep there, because libvirt just before running a
domain tries to execute qemu with some arguments (e.g. -help) to qeury
its capabilities. And you don't want your hook script to delay that.

So you need something like this:

if [ $2 == "start" ]; then
sleep 5
fi

> Thanks
>
> Jeff
>
> _______________________________________________
> libvirt-users mailing list
> libvirt-users@redhat.com
> https://www.redhat.com/mailman/listinfo/libvirt-users

Michal

------------------------------

Message: 6
Date: Mon, 13 Jun 2011 11:42:44 -0400
From: Whit Blauvelt <whit.virt@transpect.com>
To: libvirt-users@redhat.com
Subject: [libvirt-users] hook scripts - not in Ubuntu packages?
Message-ID: <20110613154244.GA28777@black.transpect.com>
Content-Type: text/plain; charset=us-ascii

On Mon, Jun 13, 2011 at 05:21:02PM +0200, Michal Privoznik wrote:

> Your other option is to create hook script:
> http://libvirt.org/hooks.html

That looks useful.

On several Ubuntu systems, with Ubuntu libvirt 0.8.8 and 0.8.3 packages
installed, there's no libvirt/hooks/ directory at all. Is this a directory
that can simply be created and used under libvirt, or does using this
feature on Ubuntu require custom installation?

Thanks,
Whit

------------------------------

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