hi all, I have a question: Is it possible to kexec into a xen vmm from a non-xen kernel? In my vision it would be interesting to boot from a generic linux installer, then analyze the hardware and boot into a suitable xen kernel, that loads a dom0 linux kernel. Do you know anybody interested in this? thanks in advance -- Jakob _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> I have a question: Is it possible to kexec into a xen vmm from a non-xen > kernel? In my vision it would be interesting to boot from a generic > linux installer, then analyze the hardware and boot into a suitable xen > kernel, that loads a dom0 linux kernel.Yes, that should be doable. Tim Deegan wrote a patch that allowed kexec to boot multiboot images like Xen. I believe it''s been in the upstream kexec tools for quite a while. You specify Xen as the kernel, followed by XenLinux as a module and (optionally) an initrd (as another module).> Do you know anybody interested in this?What sort of applications were you thinking of? Selecting between 32-bit, PAE and 64-bit perhaps? Within one architecture / paging mode it''s possible to use the normal Linux strategy of including a "standard" Xen image and then a dom0 Linux kernel with *lots* of modules for all the possible hardware. Cheers, Mark -- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi Mark, thanks for your information. Mark Williamson wrote:>> I have a question: Is it possible to kexec into a xen vmm from a non-xen >> kernel? In my vision it would be interesting to boot from a generic >> linux installer, then analyze the hardware and boot into a suitable xen >> kernel, that loads a dom0 linux kernel. > > Yes, that should be doable. Tim Deegan wrote a patch that allowed kexec to > boot multiboot images like Xen. I believe it''s been in the upstream kexec > tools for quite a while. You specify Xen as the kernel, followed by XenLinux > as a module and (optionally) an initrd (as another module).That sounds very interesting.> >> Do you know anybody interested in this? > > What sort of applications were you thinking of? Selecting between 32-bit, PAE > and 64-bit perhaps?I am trying to build a cheap xen cluster. And I thought of booting various computers using a generic bootable image (.e.g live-cd) and then prepare the network environment and boot into a xen vmm form the existing system. This allows us to deploy updates on the shared storage (e.g. nfs) without adding the need to update the cd-roms. -- Jakob _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Fri, May 18, 2007 at 12:44:06PM +0200, Jakob Praher wrote:> hi all, > > > I have a question: Is it possible to kexec into a xen vmm from a non-xen > kernel?Yes, it''s possible. I have a few systems booting via rembo that, when requested, kexec xen + kernel + initrd. I couldn''t make kexec include any arguments to the new kernel, though, so I appended a new file to the initrd with those (it''s a cpio archive). It could be limited to my hardware or a bug since corrected, but beware of it. -- lfr 0/0 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> >> I have a question: Is it possible to kexec into a xen vmm from a non-xen > >> kernel? In my vision it would be interesting to boot from a generic > >> linux installer, then analyze the hardware and boot into a suitable xen > >> kernel, that loads a dom0 linux kernel. > > > > Yes, that should be doable. Tim Deegan wrote a patch that allowed kexec > > to boot multiboot images like Xen. I believe it''s been in the upstream > > kexec tools for quite a while. You specify Xen as the kernel, followed > > by XenLinux as a module and (optionally) an initrd (as another module). > > That sounds very interesting.This stuff was in place for Xenoboot. Given your chosen use case you might actually want to take a look at that - it''s basically a livecd based bootloader using kexec (with multiboot support). It might give you some ideas, and perhaps some of it will fit with the sorts of things you want to do... It''s not designed to host VMs itself, though. VMknoppix may be worth checking out in that respect, or the Xen demo CD (I think Tim did this too, actually!)> >> Do you know anybody interested in this? > > > > What sort of applications were you thinking of? Selecting between > > 32-bit, PAE and 64-bit perhaps? > > I am trying to build a cheap xen cluster. And I thought of booting > various computers using a generic bootable image (.e.g live-cd) and then > prepare the network environment and boot into a xen vmm form the > existing system. This allows us to deploy updates on the shared storage > (e.g. nfs) without adding the need to update the cd-roms.Ah, cool :-) So dom0 would be running entirely off the CD-ROM? Where are the VMs booting from? Bear in mind that NFS root on Linux is reputedly a bit dodgy... And using loopfile-backed VM disks off NFS is a definite no-no... Although with tap:aio devices maybe it would be OK... In any case: you might want to look at network block stores if you want migration to work well. There''s a gnbd hotplug script included in the Xen distribution which should automatically manage making connections to the server and handle migration. There were some theoretical problems with shared block stores and migration (including Write-After-Write hazards, I think...) but these may have been eliminated now. Good luck! Cheers, Mark -- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Philippe Trolliet
2007-May-21 20:06 UTC
[Xen-users] logical volumes, virt-install and snaphots
hi, i´m using Fedora Core 6 as dom0 and domU. is it possible to use virt-install with logical volumes created in the dom0? is there any howto out there how this works? the purpose of this is, that i want to make snapshots from those domU-lv´s in the dom0. regards philippe _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Daniel P. Berrange
2007-May-21 20:11 UTC
Re: [Xen-users] logical volumes, virt-install and snaphots
On Mon, May 21, 2007 at 10:06:09PM +0200, Philippe Trolliet wrote:> hi, > i´m using Fedora Core 6 as dom0 and domU. is it possible to use > virt-install with logical volumes created in the dom0? is there any > howto out there how this works? > the purpose of this is, that i want to make snapshots from those > domU-lv´s in the dom0.Sure, the --file parameter to virt-install will happily accept a path to a plain file, a raw partition or an LVM volume. In retrospect it would have been better called --disk :-) # virt-install \ --name demo \ --ram 500 \ --file /dev/VolGroup00/DemoVM \ --location http://download.fedora.redhat.com/pub/fedora/linux/core/6/x86_64/os/ \ --paravirt \ --vnc 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 -=| _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Philippe Trolliet
2007-May-22 00:37 UTC
Re: [Xen-users] logical volumes, virt-install and snaphots
Daniel P. Berrange wrote:> On Mon, May 21, 2007 at 10:06:09PM +0200, Philippe Trolliet wrote: >> hi, >> i´m using Fedora Core 6 as dom0 and domU. is it possible to use >> virt-install with logical volumes created in the dom0? is there any >> howto out there how this works? >> the purpose of this is, that i want to make snapshots from those >> domU-lv´s in the dom0. > > Sure, the --file parameter to virt-install will happily accept a path to > a plain file, a raw partition or an LVM volume. In retrospect it would > have been better called --disk :-) > > # virt-install \ > --name demo \ > --ram 500 \ > --file /dev/VolGroup00/DemoVM \ > --location http://download.fedora.redhat.com/pub/fedora/linux/core/6/x86_64/os/ \ > --paravirt \ > --vnc >ok, i´ve already done that. but i can´t access the partition/logical volume directly. in the partitioning dialog of the setup i just can access the xvda-Device. why can´t i access my logical volumes directly with virt-install? philippe _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users