On 02/06/2012 12:34 PM, Michael DeHaan wrote: > > On Monday, February 6, 2012 at 11:37 AM, Cole Robinson wrote: > >> On 02/06/2012 10:58 AM, Michael DeHaan wrote: >>> Cole -- >>> >>> What's the workaround to auto-start Xen PV's? (or is there not a way?) >>> >>> Seems like we could just implement this however needed (if xenpv⊠do this >>> insteadâŠ), if virtinstall won't do it for us. >> >> The autostarting code could just be conditionally enabled if virt-install is >> new enough (just a grep of the help output) so that's not the issue. >> >> The issue is that current koan code manually passed a kernel + initrd for the >> PV guest to boot. That's the only install scenario for PV guests AFAICT. And >> this is only available via the virt-install in a version newer than what's in >> RHEL5. > > That's also how the virt installs work for everything else in koan, including > qemu/KVM. > > (Maybe I'm misunderstanding something?) >
This is my understanding of the current code. Xen FV: always does a PXE boot (so guest is actually talking to PXE server): https://github.com/cobbler/cobbler/blob/master/koan/xencreate.py#L80 Xen PV: Libvirt tells the guest to boot directly off the kernel/initrd pair specified in profile_data["kernel_local"] and profile_data["initrd_local"]: https://github.com/cobbler/cobbler/blob/master/koan/xencreate.py#L88 (are those kernel_local + initrd_local values filled in by cobbler or does the user need to manually specify them?) QEMU/KVM has two install options: if profile_data["file"] is present, boot off it like a cdrom: https://github.com/cobbler/cobbler/blob/master/koan/qcreate.py#L101 if profile_data["install_tree"] is present, pass the URL off to virtinst and have it use it's tree probing to fetch kernel + initrd: https://github.com/cobbler/cobbler/blob/master/koan/qcreate.py#L121 My implementation preserves this behavior, but in reality Xen FV and Qemu can all boot from tree/kernel, cdrom, and pxe. Xen pv can only boot from tree/kernel (which is the same thing basically). My suggestion was to adapt xen pv to behave as qemu does with "install_tree". >> >> The workaround could be to make PV installs work like qcreate >> install_location >> installs, which is basically the same as direct kernel/initrd boot but you >> rely on virt-install to pull the kernel/initrd from the install tree. > > Just trying to make sure this wouldn't break anyone. > > The install tree location isn't actually required in Cobbler, it's only a > parameter to the kickstart ⊠Are you saying we'd have to use the install > tree method *only* for Xen PV? If so, that might be an acceptable > limitation⊠if Xen FV or qemu/KVM requires the tree to find the > kernel/initrd that seems bad to me, because we deal with a lot of arbitrary > distros that express install tree locations in different ways. > If you have a new enough virt-install, you can pass in arbitrary kernel/initrd path. However current koan has never done that for qcreate, it just passes the tree location off to virtinst. In practice, virt-install actually knows how to pull kernel/initrd from fedora, rhel, opensuse, sles, debian, ubuntu, mandriva/mageia and we regularly validate this against a test suite so it's historically resilient. Of course virtinst and cobbler are duplicating functionality here but hopefully a lot of that will end up in libosinfo over time. > ks_meta["tree"] gives you this if someone had ran "Cobbler import" previously. > > If we can avoid using that when we don't have to, that would be good⊠> >> Since >> cobbler tracks this info it would probably 'just work' with a tiny patch but >> someone would need to test. And this has been supported on virt-install >> command line since probably rhel5.1 > > "it" == making autostart work for Xen PV, right? > No, autostart is not the issue here. The issue is getting guests to actually install. The autostart piece is just recent functionality to cobbler that currently brok all installs on RHEL5 host. Fixing this would be a fairly trivial patch on top of current koan or my code. The more interesting piece is making xen PV installs actually work on RHEL5 where virt-install is not new enough to provide the cli option needed to have parity with current xen PV installation, which requires passing a local kernel + initrd path to boot from. Sorry if that isn't clear. Thanks, Cole _______________________________________________ cobbler mailing list cobbler@lists.fedorahosted.org https://fedorahosted.org/mailman/listinfo/cobbler
