1 2 Previous Next 20 Replies Latest reply on Jan 22, 2012 2:53 PM by mfelker

    Instantly switch between linux and XP hosts

    UlyssesOfEpirus Hot Shot

      May be asking for too much, but is it possible to instantly switch between a linux host and a windows host?

       

      Someone must have thought of a way to do this. Apple maybe?

       

      What about automatically hibernating one host and de-hibernating the other at the press of a button?

        • 2. Re: Instantly switch between linux and XP hosts
          UlyssesOfEpirus Hot Shot

          No, I mean host.  Can't an o/s be denied half its memory?

          • 3. Re: Instantly switch between linux and XP hosts
            UlyssesOfEpirus Hot Shot

            What if memory is split in 3 parts:

             

            1. one third for running o/s, either linux or xp

            2. one third for the hibernation file of linux,

            3. one third for the hibernation file of xp

             

            Tweaking something very low-level obviously.

            • 4. Re: Instantly switch between linux and XP hosts
              WoodyZ Guru

              UlyssesOfEpirus wrote: No, I mean host.

               

              The Host is the Physical Machine and the Guest is the Virtual Machine so if indeed you're talking about two Hosts then what does "Instantly switch between linux and XP hosts" have to do with VMware Workstation!?

              • 5. Re: Instantly switch between linux and XP hosts
                UlyssesOfEpirus Hot Shot

                It's that guys hanging around these forums may have a detailed understanding of virtualization ie what machine code is running to switch between virtual machines a million times a second. And therefore must have an idea how the switching between hosts rather than VM's could possibly be done and the hardware obstacles to this (such as real-mode versus whatever).

                 

                Or is there a subforum available where the developers of vmware can be contacted?

                • 6. Re: Instantly switch between linux and XP hosts
                  AttilaSzamos Novice

                  In VMware terminology: 'Host' is the hosting operating system, so on a single hardware there can be only ONE host operating system. There cannot be any 'switching' between 'hosts'. The 'host' operating system runs the 'guest' operating system.

                  In ESX environment the host OS is the ESX itself.

                  In Workstation environment the host OS is the operating system you installed to your laptop (e.g: windows XP).

                   

                  Xen has a bare metal hypervisor product: XenClient  http://www.citrix.com/English/ps2/products/product.asp?contentID=2300325

                  I have heard that VMware is going to release a product like this.

                   

                  But in this case the situation is the same: there can be only one 'host', and in this case, the Xen is that.

                  • 7. Re: Instantly switch between linux and XP hosts
                    UlyssesOfEpirus Hot Shot

                    Xen is for a linux host supervising linux guests, is vmware going to do the equivalent with windows xp supervising xp and linux guests?

                     

                    "on a single hardware there can be only ONE host operating system"

                     

                    Let's not get stuck with definitions, the idea I'm talking about is NOT virtualization.  It just needs the detailed cpu understanding that virtualization's developers have.

                     

                    I only used the word "host" to prevent the "guests can already do that" response. But also because I want to run vmware workstation and various VM's on both host options. Having to reboot to switch between the two hosts takes too long.

                    • 8. Re: Instantly switch between linux and XP hosts
                      WoodyZ Guru

                      If you have 2 Hosts meaning 2 physical machines and you want to switch between them then use a KVM Switch.

                       

                      If you're talking about 1 Host as in 1 physical machine that physically dual boots to either Windows XP or Linux then only one physically installed OS on a physical machine can be booted at one time therefore the paradigm you're eluding to doesn't exist and even if it did it has not to do with VMware Workstation in the context you've presented here, so why are attempting to discuss nonexistent hardware technologies in virtuialzation forum?.

                      • 9. Re: Instantly switch between linux and XP hosts
                        UlyssesOfEpirus Hot Shot

                        "why are you attempting to discuss nonexistent hardware technologies in virtualization forum"


                        Gave the reason in the edit of the previous post, here it is again:

                         

                        "... is NOT virtualization.  It just needs the detailed cpu understanding that virtualization's developers have"

                         

                        And let's face it, the inventor of virtualization did not go "why waste time investigating non-existent hardware technologies?". Or "640k of ram should be enough for most applications".

                        • 10. Easily Done: Instantly switch between linux and XP (not as "hosts" though)
                          BitOBear Enthusiast

                          Other respondents are getting hung up on your use of terminiology.

                           

                          Your question actually pertains to "hardware virtualization" and so the use of "Linux Host" and "XP host" is triggering the imporper corrections...

                           

                          That said, I think what you want is ESX (or GSX?). Basically the a slim hypervsor is installed in the machine, this software "partitions" the hardware such that particular fractions of memory and various disk devices or partitions are assigned to the various virtual partitions. Then different operating system instances can be installed in each instance.

                           

                          In such a setup then, one computer is running more than one full operating system. Since none of the operating systems are subordinate to any other the "host" vs "guest" terminology does not apply.

                           

                          In Host OS + many Guest OS configs (such as vmware player or vmware workstation) the guests are called guests because, for example, the guest OS disk operations pass through the host OS's disk queue managment and so on. This forms a hirearchy.

                           

                          In partitioned hardware, each installed operating system is completely unaware of and insulated against all the of its peers. Their requests pass directly to the hypervisor. In this case there is no hirearchy, just a list of peers.

                           

                          So drop the "host" and "guest" terminology and go look at the the server and hardware virtualization products.

                           

                          Note that these hypervisor technologies are likely to be more expensive as they have a generally higher level of complexity and craftsmanship. But these dedicated hypervisors are also much faster and more efficent as there is no need to translate requests and actions from guest operations to host operations and so forth.

                          • 11. Re: Instantly switch between linux and XP hosts
                            continuum Guru
                            vExpertCommunity Warriors

                            switch between hosts ... ?

                             

                            ok - lets consider you have a windows setup and a linux setup on one machine.
                            Both OS are somehow running ... and can exist in a suspended state ready to start any time ...

                             

                            very vague ... but for arguments sake lets think on

                             

                            Who then does the switching between both states ???

                             

                            ... and again you have to introduce another host-OS - one that does the switching and managing of the different states ...

                             


                            By the way - I don't think that you really want to switch between hosts - I guess you  want VMs that are good enough so that you no longer need a host in the traditional way

                            • 12. Re: Easily Done: Instantly switch between linux and XP (not as "hosts" though)
                              UlyssesOfEpirus Hot Shot

                              Regarding ESX, unfortunately a second computer would have to be bought here to control it, and I am also put off by the fact that video and graphics are transmitted via an ethernet cable which must make it unsuitable for many applications. But let's say we go to ESX anyway.

                               

                              If the new computer has a VT-x cpu and running VM's at full speed, will the 5-year old controlling computer give a full speed experience to the user? Or better off with vmware workstation on the new computer?  Not with windows 7 but with 64bit linux as the host, specifically a very lean variant of 64bit ubuntu?

                              • 13. Re: Easily Done: Instantly switch between linux and XP (not as "hosts" though)
                                UlyssesOfEpirus Hot Shot

                                "I guess you  want VMs that are good enough so that you no longer need a  host in the traditional way"

                                 

                                That's true, yes, I want the fastest possible VM's. But I also want to experiment with all sensible host options, and ESX does not seem to be one for my applications and hardware.

                                 

                                So the change of subject as above is wrong. I want hardware details to understand what is or is not possible with an x86 cpu.

                                • 14. Re: Instantly switch between linux and XP hosts
                                  UlyssesOfEpirus Hot Shot

                                  "Who then does the switching between both states ???"

                                   

                                  Aha, there you go then, the idea of a hypervisor is born that is even simpler than ESX.  Where one VM has full access to the computer at a time, at full speed, and the other VMs are frozen.  So peripheral interfacing is then much simpler, all peripherals are completely owned by the running VM.

                                   

                                  It is only when switching between o/s's that the state of the peripherals has to be saved and restored, which is what hibernation technology already includes, so hibernation is proof that instant switching between operating systems is possible.  Hibernation saves memory to disk, but what is there to force it to store memory to disk and not some reserved memory, reserved at a level lower than the ramdisk concept?

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