hi, i am new to xen. pls. guide me what is best os should be used with xen. also let me know if there is any baremetal xen hypervisor available as i read that i require one OS on which xen hypervisor will be installed. want to use it with 32 bit machine. thanks for your help. -- With Best Wishes Balwant _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Tue, Mar 30, 2010 at 10:35 AM, balwant singh <bsingh21@gmail.com> wrote:> also let me know if there is any baremetal xen hypervisor available as i > read that i require one OS on which xen hypervisor will be installed.not exactly true. the Xen hypervisor is as bare-metal as there is: it''s loaded by GRUB and takes over the whole machine before any other kernel. .... but.... it doesn''t handle most of the hardware. essentialy, it only manages the CPU, RAM, and arbitrates access to PCI. For everything else (hard disks, network, USB, filesystems, etc) it relies on userlevel processes running on Dom0 Dom0 is in fact as much a VM as any other one running on the machine; the only differences are: - it''s started right after the Xen hypervisor, usually with parameters given to Xen via GRUB - by default Xen allows Dom0 total access to all PCI hardware - it runs the Xen userlevel processes to provide hardware access to Xen and DomU''s By delegating hardware access to Dom0, it avoids having to include lots and lots of hardware drivers in the Xen source code. As a counter example, check the ''hardware compatibility'' page of VMWare most expensive options. you''ll see it supports a limited set of network and SCSI cards. Xen, on the other hand, support almost everything that Linux supports. -- Javier _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Javier Guerra Giraldez wrote:>Dom0 is in fact as much a VM as any other one running on the machine; >the only differences are:That´s a new information for me. Does that mean that the performance of processes in Dom0 ist not better or worse than those in any DomU? I thought that Dom0 processes have a better latency and general performance compares to those in a DomU. ___________________________________________________________ WEB.DE DSL: Internet, Telefon und Entertainment für nur 19,99 EUR/mtl.! http://produkte.web.de/go/02/ _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
The Dom0 has direct access to hardware, so in general IO operations should be faster (better latency). DomUs access to hardware is provided by hypervisor using Dom0 - so the bits have "longer" way to roam out of the VM to real hardware. -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of forwebonly@web.de Sent: Wednesday, March 31, 2010 11:32 AM To: balwant singh; Javier Guerra Giraldez Cc: xen-users@lists.xensource.com Subject: Re: [Xen-users] bare metal xen hypervisor Javier Guerra Giraldez wrote:>Dom0 is in fact as much a VM as any other one running on the machine; >the only differences are:That´s a new information for me. Does that mean that the performance of processes in Dom0 ist not better or worse than those in any DomU? I thought that Dom0 processes have a better latency and general performance compares to those in a DomU. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users