Hi, I am looking around to find an ISP that provides Xen VM, so I can run whatever OS I want inside the rented guest VM. A question: have anybody seen an ISP that prohibits to run nested hypervisor (Xen in this case) inside the rented guest VM? Or they usually allow us to do anything with our VM? In case they are OK with that, I can install Xen inside the guest VM, I plan to run several few VMs on Xen there, so my guest VM is more or less like a normal physical machine hired from that ISP. And in case your ISP doesnt allow that, that would be interesting to know the reason. Please share that if you can. Thanks, Jun _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fajar A. Nugraha
2009-Dec-15 02:24 UTC
Re: [Xen-users] Prohibit to run Xen inside guest VM?
On Tue, Dec 15, 2009 at 9:09 AM, Jun Koi <junkoi2004@gmail.com> wrote:> Hi, > > I am looking around to find an ISP that provides Xen VM, so I can run > whatever OS I want inside the rented guest VM.usually you don''t get to run "whatever OS". Amazon EC2 is a good example. Look at what OS they support.> > A question: have anybody seen an ISP that prohibits to run nested > hypervisor (Xen in this case) inside the rented guest VM? Or they > usually allow us to do anything with our VM?Technically the only way you could run nested Xen is by using a HVM domU. Even then you''d get close to dead snail performance, and you can only have PV guests.> > In case they are OK with that, I can install Xen inside the guest VM, > I plan to run several few VMs on Xen there, so my guest VM is more or > less like a normal physical machine hired from that ISP.You might be better of with managed dedicated servers. Seriously. It''s available under $100/mo (search "dedicated server" on google). However, if you plan to use it for Xen, I highly recommend you get ones with remote console, which might be somewhat more expensive. -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Tue, Dec 15, 2009 at 11:24 AM, Fajar A. Nugraha <fajar@fajar.net> wrote:> On Tue, Dec 15, 2009 at 9:09 AM, Jun Koi <junkoi2004@gmail.com> wrote: >> Hi, >> >> I am looking around to find an ISP that provides Xen VM, so I can run >> whatever OS I want inside the rented guest VM. > > usually you don''t get to run "whatever OS". Amazon EC2 is a good > example. Look at what OS they support.The point is: once I control my VM, I can replace the OS anytime, no? How can they enforce that? (Suppose that they give me the HVM)> Technically the only way you could run nested Xen is by using a HVM > domU. Even then you''d get close to dead snail performance, and you can > only have PV guests.Why we can only have PV guests, but not HVM? I know that currently nested hypervisor is not good in performance, but that might very well change in the future.> > You might be better of with managed dedicated servers. Seriously. It''s > available under $100/mo (search "dedicated server" on google). > However, if you plan to use it for Xen, I highly recommend you get > ones with remote console, which might be somewhat more expensive.Thanks for this advice. Best, Jun _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fajar A. Nugraha
2009-Dec-15 05:37 UTC
Re: [Xen-users] Prohibit to run Xen inside guest VM?
On Tue, Dec 15, 2009 at 10:30 AM, Jun Koi <junkoi2004@gmail.com> wrote:> On Tue, Dec 15, 2009 at 11:24 AM, Fajar A. Nugraha <fajar@fajar.net> wrote: >> On Tue, Dec 15, 2009 at 9:09 AM, Jun Koi <junkoi2004@gmail.com> wrote: >>> Hi, >>> >>> I am looking around to find an ISP that provides Xen VM, so I can run >>> whatever OS I want inside the rented guest VM. >> >> usually you don''t get to run "whatever OS". Amazon EC2 is a good >> example. Look at what OS they support. > > The point is: once I control my VM, I can replace the OS anytime, no? > How can they enforce that? > (Suppose that they give me the HVM)That depends. Do they allow you to change domU''s disks? Do they allow attaching ISO image? Do they give vnc console access? If all of those is yes, then you should be able to replace it. AFAIK they usually start with a prebuilt image.> >> Technically the only way you could run nested Xen is by using a HVM >> domU. Even then you''d get close to dead snail performance, and you can >> only have PV guests. > > Why we can only have PV guests, but not HVM? > I know that currently nested hypervisor is not good in performance, > but that might very well change in the future.HVM requires a special CPU feature (AMD-V or intel-VT) that can only be used by the hypervisor, and not by domU. Which is why you can''t have nested HVM guest or (in the case of Windows) nested Hyper-V guests. This is different from Vmware or Virtualbox, which can work (for 32bit guest OS anyway) even without the CPU feature. -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Tue, Dec 15, 2009 at 2:37 PM, Fajar A. Nugraha <fajar@fajar.net> wrote:> On Tue, Dec 15, 2009 at 10:30 AM, Jun Koi <junkoi2004@gmail.com> wrote: >> On Tue, Dec 15, 2009 at 11:24 AM, Fajar A. Nugraha <fajar@fajar.net> wrote: >>> On Tue, Dec 15, 2009 at 9:09 AM, Jun Koi <junkoi2004@gmail.com> wrote: >>>> Hi, >>>> >>>> I am looking around to find an ISP that provides Xen VM, so I can run >>>> whatever OS I want inside the rented guest VM. >>> >>> usually you don''t get to run "whatever OS". Amazon EC2 is a good >>> example. Look at what OS they support. >> >> The point is: once I control my VM, I can replace the OS anytime, no? >> How can they enforce that? >> (Suppose that they give me the HVM) > > That depends. Do they allow you to change domU''s disks? Do they allow > attaching ISO image? Do they give vnc console access? If all of those > is yes, then you should be able to replace it. AFAIK they usually > start with a prebuilt image. > >> >>> Technically the only way you could run nested Xen is by using a HVM >>> domU. Even then you''d get close to dead snail performance, and you can >>> only have PV guests. >> >> Why we can only have PV guests, but not HVM? >> I know that currently nested hypervisor is not good in performance, >> but that might very well change in the future. > > HVM requires a special CPU feature (AMD-V or intel-VT) that can only > be used by the hypervisor, and not by domU. Which is why you can''t > have nested HVM guest or (in the case of Windows) nested Hyper-V > guests.Yes, but most machines now already have virtualization capable CPU. I dont think the ISP uses very old machine that is without VT-x or AMD-V. I have some more questions: 1) Is it true that usually ISP only provides PV machine, but not HVM? 2) On HVM case, do they usually have rany egulation on what OS can we install on that? Or we can do anything with the VM? I would be very appreciated if you can kindly advise me a good ISP providing Xen service (or please email me off list if you dont want to public that). Many thanks, J _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Tue, Dec 15, 2009 at 05:59, Jun Koi <junkoi2004@gmail.com> wrote: <---SNIP--->> I would be very appreciated if you can kindly advise me a good ISP > providing Xen service (or please email me off list if you dont want to > public that).The forums on WebHostingTalk.com are a good place to find the answer to that - those forums are all about the many aspects of hosting and you can do your research on the large number of Xen VPS providers out there. -- Please keep list traffic on the list. Rob MacGregor Whoever fights monsters should see to it that in the process he doesn''t become a monster. Friedrich Nietzsche _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fajar A. Nugraha
2009-Dec-15 07:33 UTC
Re: [Xen-users] Prohibit to run Xen inside guest VM?
On Tue, Dec 15, 2009 at 12:59 PM, Jun Koi <junkoi2004@gmail.com> wrote:>>>> Technically the only way you could run nested Xen is by using a HVM >>>> domU. Even then you''d get close to dead snail performance, and you can >>>> only have PV guests. >>> >>> Why we can only have PV guests, but not HVM? >>> I know that currently nested hypervisor is not good in performance, >>> but that might very well change in the future. >> >> HVM requires a special CPU feature (AMD-V or intel-VT) that can only >> be used by the hypervisor, and not by domU. Which is why you can''t >> have nested HVM guest or (in the case of Windows) nested Hyper-V >> guests. > > Yes, but most machines now already have virtualization capable CPU. I > dont think the ISP uses very old machine that is without VT-x or > AMD-V.The OS that''s running inside HVM domU will NOT be able to utilize intel-vt or amd-v. That''s why nested HVM domU is not possible.> > I have some more questions:As Rob said, you''d probably get better answer for those questions on another list. -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Tue, Dec 15, 2009 at 4:33 PM, Fajar A. Nugraha <fajar@fajar.net> wrote:> On Tue, Dec 15, 2009 at 12:59 PM, Jun Koi <junkoi2004@gmail.com> wrote: >>>>> Technically the only way you could run nested Xen is by using a HVM >>>>> domU. Even then you''d get close to dead snail performance, and you can >>>>> only have PV guests. >>>> >>>> Why we can only have PV guests, but not HVM? >>>> I know that currently nested hypervisor is not good in performance, >>>> but that might very well change in the future. >>> >>> HVM requires a special CPU feature (AMD-V or intel-VT) that can only >>> be used by the hypervisor, and not by domU. Which is why you can''t >>> have nested HVM guest or (in the case of Windows) nested Hyper-V >>> guests. >> >> Yes, but most machines now already have virtualization capable CPU. I >> dont think the ISP uses very old machine that is without VT-x or >> AMD-V. > > The OS that''s running inside HVM domU will NOT be able to utilize > intel-vt or amd-v. > That''s why nested HVM domU is not possible.While it is not possible at the moment due to technical reason, I think that will be OK in the future version of Xen. (Some people are working on it, I believe)> >> >> I have some more questions: > > As Rob said, you''d probably get better answer for those questions on > another list. >I havent seen what "Rob" said. His email didnt get to the list? Thanks, J _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Jun Koi wrote:> While it is not possible at the moment due to technical reason, I > think that will be OK in the future version of Xen. > (Some people are working on it, I believe)already working in KVM (still experimental, but fully working) -- Javier _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
[CCing Jun] On Tue, Dec 15, 2009 at 07:44, Jun Koi <junkoi2004@gmail.com> wrote:> > I havent seen what "Rob" said. His email didnt get to the list?For others to have seen my email it had to have got to the list. Check your junk mail folder. -- Please keep list traffic on the list. Rob MacGregor Whoever fights monsters should see to it that in the process he doesn''t become a monster. Friedrich Nietzsche _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Tue, Dec 15, 2009 at 09:22, Jun Koi <junkoi2004@gmail.com> wrote:> > It is not even in my junk folder. Could you cc again?http://lists.xensource.com/archives/html/xen-users/2009-12/msg00375.html -- Please keep list traffic on the list. Rob MacGregor Whoever fights monsters should see to it that in the process he doesn''t become a monster. Friedrich Nietzsche _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users