[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Xen vs. KVM on Debian squeeze



Hello,
I'm using xen on my system too I have an CPU like yours.
In the system are 8GB Ram
There are three domU everyone with an own ip adress (bridging) I have one domU with 512mb the other ones are with 1024mb ram.
the dom0 is running on wheezy. There are no problems at the moment.
The domU is running on wheezy too.
If your system supports Xen I would use it.
But if you know somebody who can help you with kvm if you need than use kvm.


Am 13.12.2012 09:49, schrieb Helmut Wollmersdorfer:

Am 09.12.2012 um 07:48 schrieb P. J. McDermott:

I'd like to set up virtualization on a home server with a Debian
GNU/Linux squeeze amd64 host and squeeze and wheezy amd64 guests.  I'm
trying to decide between Xen 4.0 (with paravirtualized guests and
probably the xend/xm toolstack) and qemu-kvm 0.12 or 1.1 (with the
libvirt tools).

18 months ago I decided against KVM for Xen. Main reason: missing documentation, examples and tools for KVM.

The server has two 3.0-GHz CPU cores (an AMD CPU with the AMD-V/SVM
virtualization extensions) and 2.0 GiB of RAM (which I'm planning to
either double or triple).

With Xen 4 you should not go beyond 1 GB memory for each guest. Also we experienced OOM-kills (Out Of Memory) running Dom0 with 256 or 512 MB. Now giving Dom0 1 GB it runs stable. The configuration is a failover cluster using DRBD and pacemaker. 8 VMs with a total allocation of 17 CPUs and 20 GB (hardware is 2 boxes, each has 16 CPUs, 32 GB).

We still have a machine like yours (Quadcore @2400 MHz, 4 GB) with Xen 3 in production, running 5 guests with memory allocations between 256 and 1500 MB.

I'd like to run at least five guest systems to build software, manage
mailing lists, serve files, manage a RAID 5 array using md, etc.

That would need a minimum of 6 GB.

So I need a virtualization infrastructure that offers efficient CPU and
I/O virtualization and allows guest systems to gain or forfeit virtual
memory as their loads require (pooling my limited RAM as efficiently as
possible).  (Ease of understanding and maintenance are nice as well,
though I'm happy to read documentation.)

Add as much memory as possible (double the estimated amount) -> 16 GB.


Xen used to have a userspace self-ballooning daemon called "xenballoond"
[4], but it's no longer maintained [5] and it supposedly only supports
Red Hat–family systems [6].

Forget all the memory management of running Xen-guests in squeeze/Xen4.

All things considered, I'm leaning slightly toward qemu-kvm, because it
looks like it'll do what I need in a simple and familiar way; but I'm
concerned about the performance of the CPU and I/O virtualization and
the page swapping.

Squeeze is very outdated now. If you can afford the time, try out both.

Helmut Wollmersdorfer



Reply to: