Xen vs. kvm

Just found that I didn’t do any research to compare Xen and kvm, obviously two are both announcing they perform much better than VMWare, which I believe that’s true, but I haven’t read anything about xen vs. kvm yet.

Will post something here – but I won’t do my own comparison as it will be too much to me.

Trying Proxmox

I recently spent lot of time on reading articles from Linux Magazine, as it always introduce pretty new (or not new, but less known) technology and products, this time it is Proxmox, an open source virtualization product.

I’m running VMWare Go at home at this moment, but I failed to solve the license issue and every 60 days I have to re-install everything. I guess I got the wrong ISO, so what I installed was actually for vSphere, but I just don’t want to spend too much time on digging it out as obviously VMWare does not want people get the right solution easily.

Xen is another story, at least to me it is not easy to use, maybe next version will be easier (I should take a try either but I lack of machines …). Also, I still have this impression that running Ubuntu with Xen is painful as it is, kind of, tightly bundled with RedHat distro.

Now here comes Proxmox which seems promising, I will take a try today (may be weekend as well) and then if it works I will stick with it, but if not … I will try out Xen.

Let’s see.

Performance of VMs

I used to run 4 VMs on my dual core machine but actually was running nothing seriousely. A while back I read an article from Ubuntu about its cloud setup, mentioning you should not run VMs more than number of cores you have, I was laughing at the article at that time, since it sounds ridiclous – as long as CPU can handle the load, we should run as many VMs as possible and – the bottleneck seems coming freom memory to me.

Obviously I was wrong. Once I started testing Casasandra, I got lots of timeouts from 4 VMs, I checked memory, there was no problem at all, i.e. every VM’s memory is in physical memory. I was also doubt Ubuntu is not doing as good as Fedore, obviously Iwas wrong either, then I recalled the article, shut down 2 VMs and … you know, things work like a chime.

There could be saomew thesis telling why CPU is the bottleneck, but I don’t have time to dig it out, the most important lesson I took from this case is, don’t take anythingn in granted, respect preofessional advices