> > > On 01/26/2012 01:12 AM, Peter Peltonen wrote: >> Hi, >> >> On Thu, Jan 26, 2012 at 8:44 AM, Casey Price<ca...@smileglobal.com> >> wrote: >>> I'm curious to hear which hypervisors some of you guys are using for >>> virtualizing QMT or just VMs in general. I played around with Citrix >>> XenServer for a good 6-8 months last year, very very briefly checked >>> out >>> Hyper-V, and currently am running Xen on CentOS 5.7 on a few of my >>> PowerEdge >>> 2650's. I also briefly tried out VMware's free one...ESXi? >>> >>> >From what I've been hearing, KVM is supposed to be the new up and >>> coming >>> standard. I haven't used it at all and don't know much about it, but I >>> was >>> hoping to get some recommendations from others on here. Someone >>> mentioned >>> Proxmox on here a few weeks back, so I downloaded Proxmox VE 1.9 and >>> installed it on a server I just recently bought the other night. >>> >>> That's about as far as I've gotten with it at this point, so maybe >>> someone >>> can provide some insight? >> I've ran my toaster in a centos5 + xen combination and been quite >> happy with it. No stability or perfomance issuses whatsoever. >> >> Xen is not officially supported in rhel/centos version 6, but there is >> a 3rd party repository for the kernel/xen packages and those have been >> working with ok for my dom0 and web server domUs. As qmailtoaster does >> not support centos6 yet, I havent tried installing a toaster on >> centos6 domU though. >> >> I would be interested in trying out KVM, but for me it has seemed >> still a bit immature, so I went with 3rd party Xen. And as time >> resources are limited I don't want to waste time learning another >> technology as I have a working solution with Xen. >> >> Regards, >> Peter >> >> --------------------------------------------------------------------------------- >> Qmailtoaster is sponsored by Vickers Consulting Group >> (www.vickersconsulting.com) >> Vickers Consulting Group offers Qmailtoaster support and >> installations. >> If you need professional help with your setup, contact them >> today! >> --------------------------------------------------------------------------------- >> Please visit qmailtoaster.com for the latest news, updates, and >> packages. >> >> To unsubscribe, e-mail: >> qmailtoaster-list-unsubscr...@qmailtoaster.com >> For additional commands, e-mail: >> qmailtoaster-list-h...@qmailtoaster.com >> >> > Excuse the stupid question, but what's the advantage of VM over > hardware? Are you running multiple instances of VM? Isn't there a > performance loss over hard iron when running multiple instances? > Nah, not stupid if you haven't had the need. VM allows one iron box server (Host) to run multiple instances of other servers (Guests) within it. Those guests can be anything from Windows, Linux, workstation, server, I think even MAC but not sure.
The gain is where most time a hard box running something like mail or database might spend it's life at 10% load or less. Why waste the other 90%? Also, why have the duplicate hardware like drives, power supplies, etc. Just to help visualize, I'm running VSphere 4.1. I have 2 quad core dual xeon socket servers with 16G in each. For storage, there's a NAS box (Qnap) with 4Tb sharing out NFS shares. On those shares are the files for my VM guests. The 2 servers (hosts) reach into the NFS and run the guests much like you run instances of Word, Excell, etc. Within those 2 hosts, I have a total of I think 10 guests all running. Web servers, mail servers, database servers, etc. Very cool huh? As they say, you aint seen nothin' yet. Here's where the magic comes in... Since both hosts are same hardware and they are managed centrally, if one host drops dead, within seconds the other host picks up the dead hosts running guest servers. Just like clustering but for the whole server not just an application. Also, if one of the guests starts getting out of hand and eats up the hosts resources, other guests will migrate to the other host to give it room. All AUTOMAGICALLY!!
