On Mar 2, 2011, at 12:29 PM, Rudi Ahlers <Rudi at SoftDux.com> wrote: > I am busy setting up some XEN servers on a SAN for high availability > and Cloud Computing, and thought it could be cool to setup > virtualization on a CentOS 5.5 Desktop, running on a Core i3 + 4GB > RAM, and use the SAN's storage to see if it could actually be worth my > while to replicate a Cloud Computing setup in the office. And, cause I > got a bit bored waiting for a few RAID-sets to finish initializing. > > So, I installed CentOS + KDE, chose the Virtualization package and > used Virtual Machine Manager to setup another CentOS VM inside CentOS > (I only have a CentOS ISO on this SAN, since we don't use Debian / > Slackware / FC / Ubuntu / etc). The installation was probably about > the same speed as it would be on raw hardware. But, using the > interface is painfully slow. I opened up Firefox and browsed the web a > bit. The mouse cursor lagged a bit and whenever I loaded a slow / > large website, it seemed asif the whole VM lagged behind. > > The Virtual Machine didn't use much resources. I allocated 1CPU core & > 512MB RAM to it > > Yes, I know that I could have used KVM, VMWare or VirtualBox, but I > wanted to use what's included already. Cause, let's face it, many > people (even though they're technically advanced users) don't know > virtualization. > > And, granted, when we install Virtual Machines on a XEN server, we > don't ever use X since the servers we run as web / email / database / > file servers, so there's no need for X. > > BUT, I want(ed) to see if this is a reality for the average desktop > user, or not really (yet?) seeing as most modern PC's have far more > CPU & RAM resources than what is actually needed by most. I'm not > talking about developers / graphic designers / etc. I'm talking about > Bob, who uses his PC for email, internet, document writing, etc and > needs to boot into Windows if he feels like playing Warcraft III or > StarCraft II, or use Pastel, etc. > > Wouldn't it be nice to run Windows, of for that matter Solaris / > FreeBSD / MAC (graphics designer) / another flavor of Linux / etc > inside your favorite Linux, and access it from the Desktop without too > much trouble? When I had Xen setup on my desktop with 4GB I setup dom0 with 1GB running X display manager xdm/kdm/gdm and ran headless X in each domU, 1GB for each VM. I then had a selection dialog on my X session in dom0 for which host to log in to and a full X session for that distribution. Sound is the only tricky part, you need a sound server in dom0 that allows sound from all VMs. This works with Xen or KVM, though the management and compartmentalization of Xen helps. Does CentOS support the shared memory pages, memory dedup, in Xen? That would allow for a lot more Linux VMs. -Ross