Right on the top of http://www.centos.org/docs/5/html/5.2/Virtualization/chap-Virtualization-Managing_guests_with_virsh.html, it seems to imply you can load/send scripts to the vm guest using virsh. Is that possible? How and what are the limitations? Can you query the vm guest?
On 07/15/2012 07:52 PM, Mauricio Tavares wrote: > Right on the top of > http://www.centos.org/docs/5/html/5.2/Virtualization/chap-Virtualization-Managing_guests_with_virsh.html, > it seems to imply you can load/send scripts to the vm guest using virsh. > Is that possible? How and what are the limitations? Can you query the vm > guest? What type of scripts are you talking about? You may be thinking more about the capabilities of what libguestfs provides, for modifying disk images. In general, virsh itself controls how to start a guest, but not the additional layers of communication (such as virtio, qemu-ga, or the libguestfs appliance app) required for a host to command a guest to do something from within the guest. -- -- Eric Blake eblake@... +1-919-301-3266 Libvirt virtualization library http://libvirt.org
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On Mon, Jul 30, 2012 at 1:50 PM, Eric Blake <eblake@...> wrote: > On 07/15/2012 07:52 PM, Mauricio Tavares wrote: >> Right on the top of >> http://www.centos.org/docs/5/html/5.2/Virtualization/chap-Virtualization-Managing_guests_with_virsh.html, >> it seems to imply you can load/send scripts to the vm guest using virsh. >> Is that possible? How and what are the limitations? Can you query the vm >> guest? > > What type of scripts are you talking about? You may be thinking more > about the capabilities of what libguestfs provides, for modifying disk > images. In general, virsh itself controls how to start a guest, but not > the additional layers of communication (such as virtio, qemu-ga, or the > libguestfs appliance app) required for a host to command a guest to do > something from within the guest. > Basic one would be in case a machine has been paused for a long time. You know as in "hey, you lazy vm! You have been sleeping for two weeks! Now your clock is way off and poor ntp can't sync it back. So, here's current date!" So that could either be done by stopping ntp and running ntpdate or actually being able to pass the host time (adjusted for the timezone the vm is supposed to be at) to the vm. > -- > Eric Blake eblake@... +1-919-301-3266 > Libvirt virtualization library http://libvirt.org >
Hi Mauricio, Perhaps the following link is what you want: http://libvirt.org/formatdomain.html#elementsTime (Time keeping) -- Regards, Alex ----- Original Message ----- From: "Mauricio Tavares" <raubvogel@...> To: "libvirt-users" <libvirt-users@...> Sent: Tuesday, July 31, 2012 2:00:40 AM Subject: Re: [libvirt-users] Using virsh to load scripts for the guest machine On Mon, Jul 30, 2012 at 1:50 PM, Eric Blake <eblake@...> wrote: > On 07/15/2012 07:52 PM, Mauricio Tavares wrote: >> Right on the top of >> http://www.centos.org/docs/5/html/5.2/Virtualization/chap-Virtualization-Managing_guests_with_virsh.html, >> it seems to imply you can load/send scripts to the vm guest using virsh. >> Is that possible? How and what are the limitations? Can you query the vm >> guest? > > What type of scripts are you talking about? You may be thinking more > about the capabilities of what libguestfs provides, for modifying disk > images. In general, virsh itself controls how to start a guest, but not > the additional layers of communication (such as virtio, qemu-ga, or the > libguestfs appliance app) required for a host to command a guest to do > something from within the guest. > Basic one would be in case a machine has been paused for a long(Continue reading)
On 07/30/2012 12:00 PM, Mauricio Tavares wrote: > On Mon, Jul 30, 2012 at 1:50 PM, Eric Blake <eblake <at> redhat.com> wrote: >> On 07/15/2012 07:52 PM, Mauricio Tavares wrote: >>> Right on the top of >>> http://www.centos.org/docs/5/html/5.2/Virtualization/chap-Virtualization-Managing_guests_with_virsh.html, >>> it seems to imply you can load/send scripts to the vm guest using virsh. >>> Is that possible? How and what are the limitations? Can you query the vm >>> guest? >> >> What type of scripts are you talking about? You may be thinking more >> about the capabilities of what libguestfs provides, for modifying disk >> images. In general, virsh itself controls how to start a guest, but not >> the additional layers of communication (such as virtio, qemu-ga, or the >> libguestfs appliance app) required for a host to command a guest to do >> something from within the guest. >> > Basic one would be in case a machine has been paused for a long > time. You know as in "hey, you lazy vm! You have been sleeping for two > weeks! Now your clock is way off and poor ntp can't sync it back. So, > here's current date!" That is something that fits better through qemu-ga, but no one has implemented it yet (cc'ing qemu-devel in case I'm misrepresenting things). Of course, if we did have a qemu-ga command for pushing the current time into the guest, then libvirt could usefully expose an API to wrap that qemu-ga command. -- -- Eric Blake eblake <at> redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org(Continue reading)
Eric Blake <eblake <at> redhat.com> writes: > On 07/30/2012 12:00 PM, Mauricio Tavares wrote: >> On Mon, Jul 30, 2012 at 1:50 PM, Eric Blake <eblake <at> redhat.com> wrote: >>> On 07/15/2012 07:52 PM, Mauricio Tavares wrote: >>>> Right on the top of >>>> http://www.centos.org/docs/5/html/5.2/Virtualization/chap-Virtualization-Managing_guests_with_virsh.html, >>>> it seems to imply you can load/send scripts to the vm guest using virsh. >>>> Is that possible? How and what are the limitations? Can you query the vm >>>> guest? >>> >>> What type of scripts are you talking about? You may be thinking more >>> about the capabilities of what libguestfs provides, for modifying disk >>> images. In general, virsh itself controls how to start a guest, but not >>> the additional layers of communication (such as virtio, qemu-ga, or the >>> libguestfs appliance app) required for a host to command a guest to do >>> something from within the guest. >>> >> Basic one would be in case a machine has been paused for a long >> time. You know as in "hey, you lazy vm! You have been sleeping for two >> weeks! Now your clock is way off and poor ntp can't sync it back. So, >> here's current date!" > > That is something that fits better through qemu-ga, but no one has > implemented it yet (cc'ing qemu-devel in case I'm misrepresenting > things). Of course, if we did have a qemu-ga command for pushing the > current time into the guest, then libvirt could usefully expose an API > to wrap that qemu-ga command. Could you setup a wiki page on qemu.org with a list of qemu-ga(Continue reading)
On 08/01/2012 07:48 AM, Anthony Liguori wrote: >>> Basic one would be in case a machine has been paused for a long >>> time. You know as in "hey, you lazy vm! You have been sleeping for two >>> weeks! Now your clock is way off and poor ntp can't sync it back. So, >>> here's current date!" >> >> That is something that fits better through qemu-ga, but no one has >> implemented it yet (cc'ing qemu-devel in case I'm misrepresenting >> things). Of course, if we did have a qemu-ga command for pushing the >> current time into the guest, then libvirt could usefully expose an API >> to wrap that qemu-ga command. > > Could you setup a wiki page on qemu.org with a list of qemu-ga > commands that libvirt would like? I gave it a shot (feel free to improve it) http://wiki.qemu.org/Features/GuestAgent/UsefulCommands -- -- Eric Blake eblake <at> redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
On Wed, Aug 1, 2012 at 7:17 PM, Eric Blake <eblake@...> wrote: > On 08/01/2012 07:48 AM, Anthony Liguori wrote: >>>> Basic one would be in case a machine has been paused for a long >>>> time. You know as in "hey, you lazy vm! You have been sleeping for two >>>> weeks! Now your clock is way off and poor ntp can't sync it back. So, >>>> here's current date!" >>> >>> That is something that fits better through qemu-ga, but no one has >>> implemented it yet (cc'ing qemu-devel in case I'm misrepresenting >>> things). Of course, if we did have a qemu-ga command for pushing the >>> current time into the guest, then libvirt could usefully expose an API >>> to wrap that qemu-ga command. >> >> Could you setup a wiki page on qemu.org with a list of qemu-ga >> commands that libvirt would like? > > I gave it a shot (feel free to improve it) > http://wiki.qemu.org/Features/GuestAgent/UsefulCommands > Dumb question: how do I create an account so I too can do some editing? > -- > Eric Blake eblake@... +1-919-301-3266 > Libvirt virtualization library http://libvirt.org >
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