[TriLUG] virtualization stacks for linux servers

[Jonathan Woodbury]

I've had Xen on Debian running server environments for years with a
lot of success and happiness.  I do tend to use and recommend
VirtualBox for running VMs on desktops.

I've really enjoyed the performance of Xen.  We've not done careful
testing, but it's been perceived around my office as noticeably faster
than VMWare ESXi, KVM, and VirtualBox, even when using CPUs with
virtualization extensions.

This really only applies to running Linux VMs, but easily my second
favorite feature of Xen is easier block device management.  I prefer
delivering virtual partitions to VMs rather than virtual whole disks.
I like than when I want to resize my disks I don't have to use tools
that alter partition tables, but rather I can use everyday volume
management and file system tools.  I've seen some things in the KVM
man page that indicates this might be possible with KVM as well.

For example, I can have a guest with ext4 on /dev/xvda3 mounted at
/tmp backed by a logical volume of 1GB.  If I resize that logical
volume to 2GB with lvresize, my guest sees this new space immediately
and I can run `resize2fs /dev/xvda3` to do an online resize of /tmp.
This wasn't possible with VMWare ESXi, and I don't think it's possible
with the OSE VirtualBox.  Incidentally, I could run that operation in
reverse and shrink /tmp.  This wasn't an option at all with VMWare
ESXi, even if I rebooted the VM.

Jonathan

On Thu, Apr 7, 2011 at 10:58 AM, William Chandler <wcchandler at gmail.com> wrote:
> I'm a hardware tester at IBM and my team tests KVM, Xen and VMware ESX.
>
> I usually tend to follow open source projects that have some kind of
> monetary interest.  The reason being the "Hit by a bus principle," which
> states that tomorrow anybody or everybody could die.  And if they do, will
> your project die along with them?  People who have money invested in
> something will probably throw more money at it to try and keep it alive --
> and as such, I usually stick to these solutions.  I'd stick to whatever a
> big corporation is pushing.  Call me a leming if you must.
>
> The attitude here seems to be very pro-KVM.
>
> - W
> --
> This message was sent to: Jonathan Woodbury <jpwoodbu at mybox.org>
> To unsubscribe, send a blank message to trilug-leave at trilug.org from that address.
> TriLUG mailing list : http://www.trilug.org/mailman/listinfo/trilug
> Unsubscribe or edit options on the web  : http://www.trilug.org/mailman/options/trilug/jpwoodbu%40mybox.org
> TriLUG FAQ          : http://www.trilug.org/wiki/Frequently_Asked_Questions
>