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[Libvir] FC5 bug with kernel/initrd paths
by Daniel Hiltgen 21 Apr '06

21 Apr '06

I just started experimenting with libvirt on FC5 and ran into something that doesn't seem quite right. I've created a VM using the xenguest-install.py script. I've tried grabbing the XML from virsh using dumpxml, but the kernel and initrd paths are invalid. Specifically: ... <os> <type>linux</type> <kernel>/var/lib/xen/vmlinuz.276riA</kernel> <initrd>/var/lib/xen/initrd.z1bslj</initrd> <cmdline>ro root=/dev/VolGroup00/LogVol00 rhgb quiet</cmdline> </os> ... (I see the same bogus paths in xm list --long) If I shut down the VM and attempt to power it back on using the API and this XML definition, it fails with: libvir: Xen Daemon error : POST operation failed: No such domain guest1i Failed to get devices for domain guest1 error: Failed to create domain If I boot up the VM, and copy the kernel and initrd image out of it's /boot partition onto the main filesystem, and tweak the XML to point to those paths, I can boot the system through libvirt, but the files are automatically deleted after I boot. Also, every time I boot using xm create, I get a different bogus kernel/initrd path. Is this expected behavior, or is there a bug/mismatch between libvirt and the underlying Xen modules in FC5? Thanks, Daniel

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[Libvir] Add a timestamp to virDomainInfo ?
by Daniel P. Berrange 19 Apr '06

19 Apr '06

The primary use of the virDomainInfo data is in calculating resource utilization over time. The CPU runtime data, however, is represented as a counter, so to calulate utilization requires some transformations. Basically subtract the CPU runtime value for time X, from the value at time Y, and divide the result by Y-X. Obviously this requires us to know the times X & Y. Currently the virDomainInfo structure does not contain this information though, so apps have to call something like gettimeofday() before virDomainGetInfo(), to record the timestamp of each virDomainInfo record. The problem is that this is a pretty poor approximation - particularly if libvirt is talking via XenD, a non-trivial period of time can pass between the call to gettimeofday() and the values for virDomainInfo actually sampled. Thus I would like to suggest that the virtDomainInfo structure be expanded to add an extra data field of type 'struct timeval' to record a high resolution timestamp. Now currently this wouldn't help accuracy all that much, since libvirt would still be filling this in much the same way as the app did. It does however, open the door to having Xen itself provide an accurate timestamp back to libvirt, which would in turn benefit apps without requiring further code change. 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 -=|

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[Libvir] libvirt.org is down
by Daniel Veillard 19 Apr '06

19 Apr '06

I will try to get it restarted tomorrow morning, sorry for the annoyance. Daniel -- Daniel Veillard | Red Hat http://redhat.com/ 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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[Libvir] Request for additional entry points
by Jim Fehlig 14 Apr '06

14 Apr '06

As discussed on the xen-cim call on 3/31, the Xen CIM provider needs some additional entry points in libvirt. I would like to open a discussion about adding the following entry points to libvirt. virDomainSetConfig(virConnectPtr conn, const char *xmlDesc) Stores the domU config data in xenstore. The domU is not running yet but enumerating domains would return the config for the domain as well as any running domains. This would support the notion of a defined but inactive virtual machine. Daniel noted that the config could be cached in libvirt, preventing (to some degree) modifying the config out-of-band prior to activating the domain. Note that the current virConnectListDomains() implies enumerating only running domains since a list of domain IDs is returned. Perhaps virConnectListDomains() will have to be expanded to include defined domains or another entry point to enumerate defined domains. Related would be activating a defined domain. Would clients get the domain config (via virDomainGetXMLDesc()) and subsequently pass it to virDomainCreateLinux() or another entry point to create a defined domain? virDomainDeleteConfig(virConnectPtr conn, const char *name) Removed domU config from xenstore (or cache). DomU no longer "exists". What if domain is active upon invocation? virDomainSetCurrentMemory(virDomainPtr domain, unsigned long memory) Adjust the current memory usage for a domain. virDomainReboot(virDomainPtr domain) Reboot the domain. virDomainMigrate(virDomainPtr domain, const char *host) ?? Not sure what can of worms might be opened by this one :-). Thoughts? BTW, I can certainly help with the effort if an agreement is reached on adding this functionality. Regards, Jim

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[Libvir] man page for virsh
by andrew puch 11 Apr '06

11 Apr '06

Enclosed is the man and the html page that were generated from POD Plain Old Doc from perl. pod2man virsh.pod.1 > virsh.1 pod2html virsh.pod.1 > virsh.html Behold the power of perl :)

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[Libvir] autogen.sh error
by Ronald Aigner 11 Apr '06

11 Apr '06

Hi all, I downloaded libvirt from CVS and tried to run autogen.sh which stops with the following error message: configure: error: Xen store library not found What else do I need? How do I implement support for another hypervisor? Where do I have to turn which screws? Thanks, Ron.

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[Libvir] Release of libvirt-0.1.0
by Daniel Veillard 10 Apr '06

10 Apr '06

I mostly finished the big internal code revamp over the week-end, this with the addition of the latest contributions makes it a good time for a new release, I also bumped up the medium release numbers, with the cleanup in the code internals I feel better now having people relying on libvirt, and while we are still far away from an 1.0.0 release, it's important to indicate the change :-) Available at the usual place i.e. ftp://libvirt.org/libvirt/ * building fixes: - --with-xen-distdir option (Ronald Aigner) - out of tree build and pkginfo cflag fix (Daniel Berrange) * enhancement and fixes of the XML description format (David Lutterkort and Jim Fehlig) * new APIs: - for Node information - Reboot * internal code cleanup: - refactoring internals into a driver model - more error handling - structure sharing - thread safety and ref counting * bug fixes: - error message (Jim Meyering) - error allocation in virsh (Jim Meyering) - virDomainLookupByID (Jim Fehlig) * documentation: - updates on architecture, and formatr - typo fix (Jim Meyering) * bindings: - exception handling in examples (Jim Meyering) - perl ones out of tree (Daniel Berrange) * virsh: - more options, create, nodeinfo (Karel Zak) - renaming of some options (Karel Zak) - use stderr only for errors (Karel Zak) - man page (Andrew Puch) Thanks to everybody who contributed to this release ! Daniel -- Daniel Veillard | Red Hat http://redhat.com/ 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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[Libvir] Re: virsh outputs to stderr(?!) why not stdout
by Karel Zak 07 Apr '06

07 Apr '06

On Thu, Apr 06, 2006 at 08:40:17AM -0400, Daniel Veillard wrote: > On Thu, Apr 06, 2006 at 02:37:37PM +0200, Karel Zak wrote: > > On Thu, Apr 06, 2006 at 11:46:57AM +0200, Jim Meyering wrote: > > > So, now I can use something like this to get a list of domain names: > > > > > > virsh list | tail -n +4 | awk '{print $2}' > > > > > > Is there some easier way? > > > > I think we can add some options to the list command: > > > > --noheader > > --nodom0 > > --cols=name,id,state,maxmem,usemem,.... > > > > without these options it will use default (current) format. I've > > already thought about this solution for the others commands (e.g. > > dominfo). I think this is a way how make it useful in scripts. > > Hum, why not discussing this on the libvir list ? Others may have > soem ideas too and this may promote virsh usage a bit ;-) Fixed :-) -- Karel Zak <kzak(a)redhat.com>

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Re: [Libvir] BUG: virDomainLookupByID fails after XenStore path discovery
by Jim Fehlig 05 Apr '06

05 Apr '06

>>> "Bryan D. Payne" <bryan(a)thepaynes.cc> 04/04/06 6:23 PM >>> >> I'm just not seeing it included in path returned by >> xs_get_domain_path(), only see /local/domain/<num> > For what it's worth, I was trying to put a patch together for this, >but I kept getting memory corruption errors. I was trying to access >the name through the xenstore as shown below... > > /* lookup is easier with the Xen store so try it first */ > if (conn->xshandle != NULL) { > char *namepath = NULL; > path = xs_get_domain_path(conn->xshandle, (unsigned int) id); > namepath = strdup(path); > strcat(namepath, "/name"); > name = xs_read(conn->xshandle, NULL, namepath, NULL); > if (namepath) free(namepath); > } My brain is not working today :-). Don't know why I didn't consider xs_read(). I'll fix up your patch and test/submit it tomorrow. I think the only problem is concatenating "/name" on the end of namepath, which has only been allocated enough memory to hold path via strdup(). Thanks, Jim

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[Libvir] BUG: virDomainLookupByID fails after XenStore path discovery
by Bryan D. Payne 05 Apr '06

05 Apr '06

I just updated to the latest CVS version of libvir. It looks like there's a bug in virDomainLookupByID. The behavior that I'm seeing is that the path variable is set and so the code never enters the block to find the value for name. Therefore, at the end of the function, the condition (ret->name == NULL) is true and it jumps into the error code and returns NULL. If I comment out the code that sets the path variable, things seem to work normally. Although, I presume that the idea was to extract the name from the path information... -bryan - Bryan D. Payne Graduate Student, Computer Science Georgia Tech Information Security Center http://www.bryanpayne.org

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