xen is no more developed? I''ve heard that xen is no more developed and kvm is more considered by users. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Quoting Mauro <mrsanna1@gmail.com>:> xen is no more developed? > I''ve heard that xen is no more developed and kvm is more considered by users. >That is not true. I think what you have heard is that RedHat has moved from Xen to KVM as their virtualization platform. Xen development is still continuing and moving at a fast pace with hope of dom0 support for inclusion in the 2.6.30 kernel. If I have mis-spoke will someone please correct me. Jon _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
It is not true at all. KVM and Xen are fundamentally different and address different problems. Xen allows for fast para-virtualization of Linux Domus, while KVM only fully-virtualizes. Nobody in his right mind would use KVM for a linux DOMu, because it would lose 75% of its performance, compared to para-virtualization. So KVM is for windows on Xen, but it will never replace Xen in the datacenter. Federico -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of jonr@destar.net Sent: Thursday, February 26, 2009 6:23 PM To: xen-users@lists.xensource.com Subject: Re: [Xen-users] I want to know if..... Quoting Mauro <mrsanna1@gmail.com>:> xen is no more developed? > I''ve heard that xen is no more developed and kvm is more considered byusers.>That is not true. I think what you have heard is that RedHat has moved from Xen to KVM as their virtualization platform. Xen development is still continuing and moving at a fast pace with hope of dom0 support for inclusion in the 2.6.30 kernel. If I have mis-spoke will someone please correct me. Jon _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
2009/2/27 Venefax <venefax@gmail.com>:> It is not true at all. KVM and Xen are fundamentally different and address > different problems. Xen allows for fast para-virtualization of Linux Domus, > while KVM only fully-virtualizes. Nobody in his right mind would use KVM for > a linux DOMu, because it would lose 75% of its performance, compared to > para-virtualization. So KVM is for windows on Xen, but it will never replace > Xen in the datacenter. > FedericoSorry for my ignorance but...can you explain? I think pure virtualization gains more in performances vs para virtualization. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
It is exactly opposite. Para-virtualization is near-native performance. Use full-virtualization only to mix windows and Linux in the same hardware. But rest assured that Hyper-V R2 achieves 2 times the performance and stability compared to KVm and Xen full-virt. I tested them all in real-life scenarios. My advice is: use Xen 3.3 for any Linux domus and only paravirtualized. And use Microsoft Hyper-v for windows on windows virtualization. -----Original Message----- From: Mauro [mailto:mrsanna1@gmail.com] Sent: Thursday, February 26, 2009 6:40 PM To: Venefax Cc: jonr@destar.net; xen-users@lists.xensource.com Subject: Re: [Xen-users] I want to know if..... 2009/2/27 Venefax <venefax@gmail.com>:> It is not true at all. KVM and Xen are fundamentally different and address > different problems. Xen allows for fast para-virtualization of LinuxDomus,> while KVM only fully-virtualizes. Nobody in his right mind would use KVMfor> a linux DOMu, because it would lose 75% of its performance, compared to > para-virtualization. So KVM is for windows on Xen, but it will neverreplace> Xen in the datacenter. > FedericoSorry for my ignorance but...can you explain? I think pure virtualization gains more in performances vs para virtualization. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Quoting Venefax <venefax@gmail.com>:> It is exactly opposite. Para-virtualization is near-native performance. Use > full-virtualization only to mix windows and Linux in the same hardware. But > rest assured that Hyper-V R2 achieves 2 times the performance and stability > compared to KVm and Xen full-virt. I tested them all in real-life scenarios. > My advice is: use Xen 3.3 for any Linux domus and only paravirtualized. And > use Microsoft Hyper-v for windows on windows virtualization. >Do you have a write up on your findings? I would be interested to read what you had discovered. Jon _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On February 26, 2009 3:32 pm Venefax wrote:> It is not true at all. KVM and Xen are fundamentally different and > address different problems. Xen allows for fast para-virtualization of > Linux Domus, while KVM only fully-virtualizes. Nobody in his right mind > would use KVM for a linux DOMu, because it would lose 75% of its > performance, compared to para-virtualization. So KVM is for windows on > Xen, but it will never replace Xen in the datacenter.I think you are confusing HVM (hardware-assisted VMs), which both KVM and Xen support, with KVM (kernel-based VM), another virtualisation system. KVM has paravirtualised network, block/storage, and console drivers for Linux and Windows. Same as Xen. There''s no "75% loss of performance". -- Freddie fjwcash@gmail.com _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
KVM requires virtualization hardware, and the hard-drive is QUEMU, slow, and they don''t even have plans to para-virtualize it. I tested the virtio drivers with the current KVM and my virtual machines blew up under pressure. It is not fully-baked yet. But let''s define the terms: Windows on Xen requires VTD, or Virtualization-hardware. That is sloooow performance compared with Microsoft Hyper-V R2, maybe a half. SMP is poor, poor. Hyper-V gives a good two way and declines exponentially after that, so the most you can do is two-way. I have over 150 windows 2003 virtual machines in production. On the other hand, Xen domu''s is Linux on Linux, and it flies. That is what I call para-virtualization, and I have over 100 of those machines. Vmware, on the other hand, is useless. For example, ESXi does fully-virtualize everything, even Linux domu''s, offering maybe 1/2 of the aggregated performance you can get with, for instance, Suse as host and Centos a Domu. Let''s be clear, Novell tech support does not "support" Centos or Red Hat as paravirtualized domu''s, but it works so much faster that you would be an idiot not to do it, and it is 100% stable I have 100% of my company''s business in paravirtualized Domu''s under Novell''s Suse. There is a powerful reason to prefer Suse as host instead of Red Hat (I have both licenses). If you have a problem, a real problem, Novell actually logs into the server and tries to understand the issue, with a human being. Red Hat is hands-off, I mean, they are not allowed to log into your server. The support is absolutely deficient for a company that cannot go down. So my 5 cents of advice is: Novell as a Host, Centos as Linux Domu or Ubuntu, if you like it (it works), and keep a separate machine for all your windows users. Do not mix them. Federico -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Freddie Cash Sent: Thursday, February 26, 2009 6:52 PM To: xen-users@lists.xensource.com Subject: Re: [Xen-users] I want to know if..... On February 26, 2009 3:32 pm Venefax wrote:> It is not true at all. KVM and Xen are fundamentally different and > address different problems. Xen allows for fast para-virtualization of > Linux Domus, while KVM only fully-virtualizes. Nobody in his right mind > would use KVM for a linux DOMu, because it would lose 75% of its > performance, compared to para-virtualization. So KVM is for windows on > Xen, but it will never replace Xen in the datacenter.I think you are confusing HVM (hardware-assisted VMs), which both KVM and Xen support, with KVM (kernel-based VM), another virtualisation system. KVM has paravirtualised network, block/storage, and console drivers for Linux and Windows. Same as Xen. There''s no "75% loss of performance". -- Freddie fjwcash@gmail.com _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Xen also allows for both para-virtualization and full virtualization of guests. I wouldn''t say that KVM would lose 75% of Linux guest''s performance, but certainly 15-20% at the least. -Nick>>> "Venefax" <venefax@gmail.com> 2009/02/26 16:32 >>>It is not true at all. KVM and Xen are fundamentally different and address different problems. Xen allows for fast para-virtualization of Linux Domus, while KVM only fully-virtualizes. Nobody in his right mind would use KVM for a linux DOMu, because it would lose 75% of its performance, compared to para-virtualization. So KVM is for windows on Xen, but it will never replace Xen in the datacenter. Federico -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of jonr@destar.net Sent: Thursday, February 26, 2009 6:23 PM To: xen-users@lists.xensource.com Subject: Re: [Xen-users] I want to know if..... Quoting Mauro <mrsanna1@gmail.com>:> xen is no more developed? > I''ve heard that xen is no more developed and kvm is more considered byusers.>That is not true. I think what you have heard is that RedHat has moved from Xen to KVM as their virtualization platform. Xen development is still continuing and moving at a fast pace with hope of dom0 support for inclusion in the 2.6.30 kernel. If I have mis-spoke will someone please correct me. Jon _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users This e-mail may contain confidential and privileged material for the sole use of the intended recipient. If this email is not intended for you, or you are not responsible for the delivery of this message to the intended recipient, please note that this message may contain SEAKR Engineering (SEAKR) Privileged/Proprietary Information. In such a case, you are strictly prohibited from downloading, photocopying, distributing or otherwise using this message, its contents or attachments in any way. If you have received this message in error, please notify us immediately by replying to this e-mail and delete the message from your mailbox. Information contained in this message that does not relate to the business of SEAKR is neither endorsed by nor attributable to SEAKR. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
I agree with the parts about para-virt native performance, but I COMPLETELY disagree with Hyper-V for performance and stability of Windows guests. I run Windows guests on my Xen 3.2.1 host (SLES10 SP2) with very good performance and no stability problems at all. Furthermore, Server 2008 is supposed to have built-in paravirtualization support that works on Hyper-V or Xen. I recommend Xen for Linux, Windows, Solaris, and BSD virtualization - VMware ESX(i) is my second choice. Don''t mean to be a Microsoft basher... -Nick>>> "Venefax" <venefax@gmail.com> 2009/02/26 16:46 >>>It is exactly opposite. Para-virtualization is near-native performance. Use full-virtualization only to mix windows and Linux in the same hardware. But rest assured that Hyper-V R2 achieves 2 times the performance and stability compared to KVm and Xen full-virt. I tested them all in real-life scenarios. My advice is: use Xen 3.3 for any Linux domus and only paravirtualized. And use Microsoft Hyper-v for windows on windows virtualization. -----Original Message----- From: Mauro [mailto:mrsanna1@gmail.com] Sent: Thursday, February 26, 2009 6:40 PM To: Venefax Cc: jonr@destar.net; xen-users@lists.xensource.com Subject: Re: [Xen-users] I want to know if..... 2009/2/27 Venefax <venefax@gmail.com>:> It is not true at all. KVM and Xen are fundamentally different and address > different problems. Xen allows for fast para-virtualization of LinuxDomus,> while KVM only fully-virtualizes. Nobody in his right mind would use KVMfor> a linux DOMu, because it would lose 75% of its performance, compared to > para-virtualization. So KVM is for windows on Xen, but it will neverreplace> Xen in the datacenter. > FedericoSorry for my ignorance but...can you explain? I think pure virtualization gains more in performances vs para virtualization. This e-mail may contain confidential and privileged material for the sole use of the intended recipient. If this email is not intended for you, or you are not responsible for the delivery of this message to the intended recipient, please note that this message may contain SEAKR Engineering (SEAKR) Privileged/Proprietary Information. In such a case, you are strictly prohibited from downloading, photocopying, distributing or otherwise using this message, its contents or attachments in any way. If you have received this message in error, please notify us immediately by replying to this e-mail and delete the message from your mailbox. Information contained in this message that does not relate to the business of SEAKR is neither endorsed by nor attributable to SEAKR. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Mauro wrote:> xen is no more developed? > I''ve heard that xen is no more developed and kvm is more considered by users.It seems like KVM developers and other folks hate Xen, and spit on it as much as they can. I don''t understand why, but that''s really not right. I have seen a stupid blog entry saying things like "Xen will never be a part of the Kernel", as if the userland tools for KVM would. Just don''t listen to the noise, and have a look to how many patch a WEEK are sent to the xen-devel list. It''s HUGE, and quite hard to follow. Now, RedHat may do whatever they want, I don''t really care. Thomas _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thomas Goirand wrote:> It seems like KVM developers and other folks hate Xen, and spit on it as > much as they can. I don''t understand why, but that''s really not right.hope it''s just the typical ''loud minority'' and not the real developers. judging from the kvm-devel list (where i also lurk), i think the attitude is of mutual respect but distance. not too different from the usual attitude here towards KVM.> I have seen a stupid blog entry saying things like "Xen will never be a > part of the Kernel", as if the userland tools for KVM would.haven''t read that one (and doesn''t sound like some good reading), but i guess it refers to the Xen hypervisor itself, which isn''t part of the kernel and shouldn''t be.> Now, RedHat may do whatever they want, I don''t really care.RedHat bought Qumranet, getting not only the core KVM developers, but also the proprietary display protocol. judging from past RedHat acquisitions (remember Sistina?), i hope they''ll open all of this. maybe it will get into qemu as an alternative to the embedded VNC server. if we believe the hype, it would be vastly more efficient, maybe on par with NX. now that''s an some benefit to Xen that might come out of RedHat''s move. -- Javier _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Can you say that for production servers is better xen rather than kvm? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Mon, Mar 2, 2009 at 4:51 AM, Mauro <mrsanna1@gmail.com> wrote:> Can you say that for production servers is better xen rather than kvm?If you''re using RHEL like I do, then from support perspective the obvious answer is (currently) yes, as Redhat provides suppot for xen guests, but not for kvm guests.>From performance perspective, the answer is also yes as xen allowsparavirtualized (PV) guests which gives higher performance and lower virtualization overhead compared to full virtualization methods (HVM or KVM guests). Regards, Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi, Xen is already in production use for many years now, you can get it under a support contract with for example Novell or Redhat or use one of the many excellent open source options (CentOS, Debian, OpenSuSE) If you feel adventurous you could also try OpenSolaris. I''m sure KVM will one day become stable and be in use more than Xen, which is a shame because Xen is much more mature. Xen will never be fully replaced though, there is too much vested interest in it (Citrix, Sun... etc) Regards, Barry On Sun, Mar 1, 2009 at 10:51 PM, Mauro <mrsanna1@gmail.com> wrote:> Can you say that for production servers is better xen rather than kvm? > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >-- Barry van Someren --------------------------------------- Linked in: http://www.linkedin.com/in/barryvansomeren Skype: BvsomerenSprout KvK: 27317624 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
2009/3/2 Fajar A. Nugraha <fajar@fajar.net>:> On Mon, Mar 2, 2009 at 4:51 AM, Mauro <mrsanna1@gmail.com> wrote: >> Can you say that for production servers is better xen rather than kvm? > > If you''re using RHEL like I do, then from support perspective the > obvious answer is (currently) yes, as Redhat provides suppot for xen > guests, but not for kvm guests.I''m using debian lenny. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi, I''m pretty much a CentOS / RHEL fan (due to being experienced with it) but I''ve given Lenny a try this weekend and it looks very well to me. Comes with a newer Kernel and integrates nicely with xen-tools and debootstrap. I''d say use what you know, unless you are using enterprise support from Redhat of course :-) Regards, Barry On Mon, Mar 2, 2009 at 9:44 AM, Mauro <mrsanna1@gmail.com> wrote:> 2009/3/2 Fajar A. Nugraha <fajar@fajar.net>: >> On Mon, Mar 2, 2009 at 4:51 AM, Mauro <mrsanna1@gmail.com> wrote: >>> Can you say that for production servers is better xen rather than kvm? >> >> If you''re using RHEL like I do, then from support perspective the >> obvious answer is (currently) yes, as Redhat provides suppot for xen >> guests, but not for kvm guests. > > I''m using debian lenny. > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >-- Barry van Someren --------------------------------------- Linked in: http://www.linkedin.com/in/barryvansomeren Skype: BvsomerenSprout KvK: 27317624 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users