-----Original Message----- From: centos-virt-bounces@centos.org [mailto:centos-virt-bounces@centos.org] On Behalf Of Ben M. Sent: Friday, January 15, 2010 10:17 AM To: Discussion about the virtualization on CentOS Subject: Re: [CentOS-virt] Xen Database vms
Thank you. Excellent thoughts all, and just the type of feedback I needed to think about. I would be going out a dedicated NIC on the data traffic, and I would do block devices in LVM for the disk IO, Windows 2008 32bit seems to be very happy with that setup in a mixed Xen environment. Under no circumstances would I run these as file images. There is no comparison to dedicated hardware for this application using file based vms. Has to be block devices.
I think for my purposes putting the database servers in Xen is absolutely worth a shot. If it works, I have a lot of benefits from it. If it doesn't, I lost some hours but gained some knowledge, and maybe a backup server.
A vpn (OpenVPN) server in Xen is part of my plan as well. I'm trying to sketch out all the lines of IO and see what I have to do to keep things snappy. _______________________________________________
By the way, if the articles on the web are true, Red Hat is going KVM for several reasons so I decided to go KVM only.
For one thing, Xen requires a modified kernel on the host. Also, I found I had to install drivers to get stats and performance from xen, and sometimes the drivers wouldn't install on some linux distros used in guests.
But with kvm, I don't need to install drivers for kvm guests. The virtual hardware presented to the OS must be done right. And theres a choice of nics that don't need additional drivers: realtek 8169, Intel e1000, etc.