On Fri, Oct 10, 2014 at 04:03:26PM +0800, Zhi Yong Wu wrote:> On Fri, Oct 10, 2014 at 3:39 PM, Richard W.M. Jones <rjones@redhat.com> wrote: > > On Fri, Oct 10, 2014 at 11:40:03AM +0800, Zhi Yong Wu wrote: > >> HI, Richard > >> > >> Is there any plan to make daemon to directly run on the hypervisor, > >> not starting a guest? e.g. directly export a guest image to be a block > >> device on the hypervisor? > > > > Not in 1.28, but adding lxc:// support to the libvirt backend > > (src/launch-libvirt.c) would be fairly easy. > > > > It's an idea that has been kicked around before on the list, eg: > > > > https://www.redhat.com/archives/libguestfs/2014-January/msg00296.html > It's not what i said, i mean that when you run virt-resize, it doesn't > start a appliance guest. You know, it will bring up a lot of troubles > or risks if a guest is started.There are no risks as far as I'm aware. What kind of troubles/risks? Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org
On Fri, Oct 10, 2014 at 4:07 PM, Richard W.M. Jones <rjones@redhat.com> wrote:> On Fri, Oct 10, 2014 at 04:03:26PM +0800, Zhi Yong Wu wrote: >> On Fri, Oct 10, 2014 at 3:39 PM, Richard W.M. Jones <rjones@redhat.com> wrote: >> > On Fri, Oct 10, 2014 at 11:40:03AM +0800, Zhi Yong Wu wrote: >> >> HI, Richard >> >> >> >> Is there any plan to make daemon to directly run on the hypervisor, >> >> not starting a guest? e.g. directly export a guest image to be a block >> >> device on the hypervisor? >> > >> > Not in 1.28, but adding lxc:// support to the libvirt backend >> > (src/launch-libvirt.c) would be fairly easy. >> > >> > It's an idea that has been kicked around before on the list, eg: >> > >> > https://www.redhat.com/archives/libguestfs/2014-January/msg00296.html >> It's not what i said, i mean that when you run virt-resize, it doesn't >> start a appliance guest. You know, it will bring up a lot of troubles >> or risks if a guest is started. > > There are no risks as far as I'm aware. What kind of troubles/risks?You can't make sure that guest never fail or panic forever, right? That is, you will have to maintain that guest, not customers' guests. This risk is beyond thought. The maintainance cost will be very expensive in our super large scale cloud environment. We are trying not to start a appliance guest when issuing a libguestfs command, such as virt-resize.> > Rich. > > -- > Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones > Read my programming and virtualization blog: http://rwmj.wordpress.com > libguestfs lets you edit virtual machines. Supports shell scripting, > bindings from many languages. http://libguestfs.org-- Regards, Zhi Yong Wu
On Fri, Oct 10, 2014 at 04:26:20PM +0800, Zhi Yong Wu wrote:> You can't make sure that guest never fail or panic forever, right?Do you mean the guest or the libguestfs appliance?> That is, you will have to maintain that guest, not customers' guests. > This risk is beyond thought. The maintainance cost will be very > expensive in our super large scale cloud environment. > > We are trying not to start a appliance guest when issuing a libguestfs > command, such as virt-resize.There may be some confusion here. Virt-resize doesn't run the guest. TBH I'm not exactly sure what your concerns are. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-builder quickly builds VMs from scratch http://libguestfs.org/virt-builder.1.html
[Please keep replies on the list to help others] On Fri, Oct 10, 2014 at 05:01:22PM +0800, Zhi Yong Wu wrote:> On Fri, Oct 10, 2014 at 4:47 PM, Richard W.M. Jones <rjones@redhat.com> wrote: > > On Fri, Oct 10, 2014 at 04:26:20PM +0800, Zhi Yong Wu wrote: > >> You can't make sure that guest never fail or panic forever, right? > > > > Do you mean the guest or the libguestfs appliance? > > > >> That is, you will have to maintain that guest, not customers' guests. > >> This risk is beyond thought. The maintainance cost will be very > >> expensive in our super large scale cloud environment. > >> > >> We are trying not to start a appliance guest when issuing a libguestfs > >> command, such as virt-resize. > > > > There may be some confusion here. Virt-resize doesn't run the guest. > When i issue virt-resize, i exactly saw one guest is started, indisk > and outdisk are attached to this guest.... > > Do you mean that in the latest upstream, virt-resize doesn't run the guest?OK so you mean the libguestfs appliance.> > TBH I'm not exactly sure what your concerns are. > > We are afraid that if a guest is started when vrit-xxx command is > issued, it will bring some unexpected risks and take too much time to > complete this command.If you have any concrete problems, then let us know. You may wish to limit the number of virt-resize processes than can run at any one time. GNU 'sem' can do this relatively easily: https://www.gnu.org/software/parallel/sem.html There are various tips on how to manage the appliance discussed in this manual page: http://libguestfs.org/guestfs-performance.1.html Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://people.redhat.com/~rjones/virt-df/