Re: [Openstack] Local storage and Xen with Libxl
On Fri, Apr 19, 2013 at 01:43:23PM +0300, Cristian Tomoiaga wrote: As for the compute part, I may need to work with libvirt but I want to avoid that if possible. Libxl was meant for stacks right ? Again, this may not be acceptable and I would like to know. Nova already has two drivers which support Xen, one using XenAPI and the other using libvirt. Libvirt itself will either use the legacy XenD/XenStore APIs, or on new enough Xen will use libxl. libxl is a pretty low level interface, not really targetted for direct application usage, but rather for building management APIs like libvirt or XCP. IMHO it would not really be appropriate for OpenStack to directly use libxl. Given that Nova already has two virt drivers which can work with Xen, I also don't really think there's a need to add a 3rd using libxl. Regarding KVM, I did not use it until now. I don't like the fact the security issues pop up more often then I would like (I may be wrong ?). There are other reasons but are not important in my decision. Having worked with both Xen KVM for 8 years now, I don't see that either of them are really winning in terms of security issues in the hypervisor or userspace. Both of them have had their fair share of vulnerabilities. In terms of the device model, they both share use of the QEMU codebase, so many vulnerabilities detected with KVM will also apply to Xen and vica-verca. So I don't think your assertion that KVM suffers more issues is really accurate. Should I go with Libxl or stick to libvirt ? Should I start to work on local storage or has someone already started and I should contact him ? As far as Nova virt drivers for Xen are concerned, you should either use the XenAPI driver, or the libvirt driver. Regards, Daniel -- |: http://berrange.com -o-http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| ___ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
Re: [Openstack] Local storage and Xen with Libxl
Got it, thank you! I'll use libvirt then. Regarding security with KVM and Xen, I've been reading too much, probably from unverified sources too. I may plan on using Ceph too and this seems to work better with KVM for now (again from reading on the Ceph mailing list). I will test everything in one or two weeks. For now I only want to get some input from the community. There is no clear winner between Xen and KVM indeed and I'm only trying to figure out what's best for my needs. ___ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
Re: [Openstack] Local storage and Xen with Libxl
Daniel P. Berrange wrote: On Fri, Apr 19, 2013 at 01:43:23PM +0300, Cristian Tomoiaga wrote: As for the compute part, I may need to work with libvirt but I want to avoid that if possible. Libxl was meant for stacks right ? Again, this may not be acceptable and I would like to know. Nova already has two drivers which support Xen, one using XenAPI and the other using libvirt. Libvirt itself will either use the legacy XenD/XenStore APIs, or on new enough Xen will use libxl. libxl is a pretty low level interface, not really targetted for direct application usage, but rather for building management APIs like libvirt or XCP. IMHO it would not really be appropriate for OpenStack to directly use libxl. Given that Nova already has two virt drivers which can work with Xen, I also don't really think there's a need to add a 3rd using libxl. Absolutely agreed, we do not want a libxl nova virt driver :). FYI, I have not tried the libvirt libxl driver on Xen compute nodes - all of my nodes are running the legacy xend toolstack and thus using the legacy libvirt xen driver. (I plan to switch these nodes to the new toolstack in the Xen 4.3 timeframe.) That said, the libxl driver should work on a Xen compute node running the libxl stack. I still haven't finished the migration patch for the libvirt libxl driver, so migration between libxl Xen compute nodes is not possible. Regards, Jim ___ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
Re: [Openstack] Local storage and Xen with Libxl
Cristian Tomoiaga wrote: Hi Jim, Thank you! I'll check libvirt in more detail to make sure nothing I need is missing. With xend it should work. I'm planning ahead and want to deploy on Libxl but for the sake of argument I will probably use both KVM (Daniel is to blame here :) ) and Xen with libxl while I test out everything. It's a good thing to see interest in libvirt. For some reason I though that libvirt will move slower with new features (granted libxl has changed from 4.1 to 4.2). Also being bugged by this: https://wiki.openstack.org/wiki/LibvirtAPI Nothing to be alarmed about IMO. That simply provides info about some of the many ongoing improvements and enhancements to the nova libvirt driver, which is the most widely used driver btw, including in all the CI gating. Regards, Jim ___ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
Re: [Openstack] Local storage and Xen with Libxl
It is true that most of the gating jobs are running on KVM but the smokestack tests also run on Xen (actually XenServer with the XenAPI driver), so there is CI testing for Xen and we'll be improving that through Havana as well. Bob -Original Message- From: Openstack [mailto:openstack-bounces+bob.ball=citrix@lists.launchpad.net] On Behalf Of Jim Fehlig Sent: 19 April 2013 13:05 To: Cristian Tomoiaga Cc: openstack@lists.launchpad.net Subject: Re: [Openstack] Local storage and Xen with Libxl Cristian Tomoiaga wrote: Hi Jim, Thank you! I'll check libvirt in more detail to make sure nothing I need is missing. With xend it should work. I'm planning ahead and want to deploy on Libxl but for the sake of argument I will probably use both KVM (Daniel is to blame here :) ) and Xen with libxl while I test out everything. It's a good thing to see interest in libvirt. For some reason I though that libvirt will move slower with new features (granted libxl has changed from 4.1 to 4.2). Also being bugged by this: https://wiki.openstack.org/wiki/LibvirtAPI Nothing to be alarmed about IMO. That simply provides info about some of the many ongoing improvements and enhancements to the nova libvirt driver, which is the most widely used driver btw, including in all the CI gating. Regards, Jim ___ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp ___ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
