Hey folks, By Paravirtualization, I mean the installation of "tools" or "guest additions" type packages, which present virtual interfaces to the guest OS. So in VMware, a component of this would mean setting "ethernet0.virtualDev = vmxnet", and having the tools modules pre-installed. A fully virtualized OS for VMware would support all that crap. From Wikipedia: """ In computing, paravirtualization is a virtualization technique that presents a software interface to virtual machines that is similar but not identical to that of the underlying hardware. Paravirtualization may allow the virtual machine monitor (VMM) to be simpler or virtual machines that run on it to achieve performance closer to non-virtualized hardware. However, operating systems must be explicitly ported to run on top of a paravirtualized VMM. Owners of proprietary operating systems may decline to allow paravirtualization for strategic purposes. """ I'm neurotic about paravirtualization because, well, we roll our organization's production systems on VMs, so I want minimal performance hit if possible across the board. I'm sure some of you are thinking right now how foolish I am for doing this. In reality, cost savings in labor through all of the flexibilities of a fully virtualized environment is more important to us than raw performance and low latency. One problem with setting your VM template to utilize virtualDevices in a production environment currently is the inability to PXE boot the machine to provision your host, because no commerical distro or operating system I know of, Linux, BSD, Solaris or otherwise, currently offers an out-of-the-box module support for virtualization in their install initrd, for various licensing and technical reasons (the open-vm-tools effort would likely solve this in the near future). OHAI Trolls who can't read: YES YOU *CAN* PXEBOOT w/VMXNET (NOT VMXNET-ENHANCED), BUT YOUR INSTALL FAILS BECAUSE IT CAN'T FIND A "DRIVER" FOR 'VMXNET'. I know of tru's efforts and others on this front and I really appreciate the knowledge they have brought to the table, but I feel that it's about time that some dedicated entity step in and 'solve' this problem (we've written kickstart+firstboot-type scripts that eliminate the 'work' of managing hundreds of VMs and their installation of tools, but through the whole process we have wished for Our Favorite Community Enterprise OS to support this stuff OOB so we didn't need to do the work. Lazy Sysadmins are lazy). One man cannot keep such a beast up to date; it needs to be a dedicated effort or project. The complexity of 'doing VMs right' is getting to the point where it requires a virtualization expert to be staffed (consider the ever-present Time Sync Issue, which requires customization on the Host configuration AND the Guest OS). This is unacceptable; we either need virtualization software that is a little more clever or we have to step in on the application layer and have the OS live closer to the host hardware. Also, there's a great deal of untapped potential in having at least a greater set of conservative message passing between the Guest OS and Host / VM Infrastructure, shared storage amongst different hosts over the attached SAN, etc etc... skies the limit. This might be a direction that Big Mommy RedHat should/would eventually take. I'm not a big fan of CentOS mini-forks of kernels myself (e.g. centosplus, -vm, etc), since it kinda defeats the 'point' if you know what I mean. /me crosses fingers that Sun + InnoTek makes a really kickass VirtualBox for the Enterprise that develops a much better solution, or better yet, a *truly* embedded virtualization solution (Hey, anyone from Sun Engineering on this mailing list? Imagine memory and storage pooling on the hardware layer over something like infiniband, guys). Then again, cloud computing, future is bright, sunglasses + igloos, teotwawki, lol. - allen tsang Daniel de Kok wrote: > On Mon, May 5, 2008 at 5:13 AM, Allen Tsang<atsang at advance.net> wrote: > >> Speaking of which, I was talking to some friends about building a fully >> paravirtualized rhel/centos that works with xen, vmware, virtualbox, etc. >> Do you guys feel like that's a product you would consider using? >> > > I suppose you mean "fully virtualized", since VMWare and VirtualBox do > not paravirtualize? If so, True provides VMWare images of CentOS 4 and > 5. They should be easy to modify for VirtualBox and qemu as well: > > http://dev.centos.org/~tru/vmware/ > > Take care, > Daniel > _______________________________________________ > CentOS-virt mailing list > CentOS-virt at centos.org > http://lists.centos.org/mailman/listinfo/centos-virt >