-----Original Message----- Fhttp://www.liveleak.com/view?i=375_1263347833rom: centos-virt-bounces at centos.org [mailto:centos-virt-bounces at centos.org] On Behalf Of Ben M. Sent: Friday, January 15, 2010 8:56 AM To: Discussion about the virtualization on CentOS Subject: Re: [CentOS-virt] Xen Database vms Neil: What if it were the only "real" active vm? I know that might sound a bit of a waste, but I am really enjoying the backup and duplication abilities of running in a Xen hypervisor as well as its other features. It seems to be saving me a lot of time in production settings. And there is also a comfort level in uniformity on a LAN. Would there still be a significant hit on resource performance by the hypervisor if running that database server alone in it, or alongside a few rarely used, lightweight or spurious vms? I am talking about the database activities running during the biz day and backups, batches and other maintenance in the off hours. Nothing urgent here, just trying to plan out the future, mull over the possibilities and where to head. - Ben -----Original Message----- I think it could work well. Having a server in a vm makes it more portable. Many of my servers and services are running in vms on two centos 5.4 servers: openfiler, efw firewall, trixbox 2.8, SME Server (in server mode for email and spamassassin), windows 2003 server, windows 2008 server, windows 7, and others that aren't running. I would suggest: If there are a lot of temp files or disk access to the OS, install the vm OS on a block device rather than to a file. The storage should be on a local block device as well. If there's a lot of lan traffic to/from the other vms, install a 3rd ethernet card in the server that is only used for db traffic. I also use a virtual network that the vms can use to reach each other. This is basically a private internal lan running across the host machine's buses, rather than through your network switch. I get native performance with my set up...