24 May 2006

Xen ... success!

Well, Ive managed to install Xen successfully, and Im actually quite pleased with the results. The new kernel boots up without a problem, and using the xmguest-install.py script which I complained about earlier (unjustly so), I managed to install a FC5 guest nicely. I tried both the GUI-based anaconda and text-based versions and they both work wonderfully. I was pleasantly surprised to see the GUI anaconda via vnc. Cheap thrills.

The purpose was to set up a virtual machine (VM) for dspam.
  1. So that it didnt interfere with the current sendmail configuration. I have been testing dspam for quite some time now, and found it works well with postfix. Also postfix seems alot nicer to administer compared to sendmail.
  2. I didnt want to commission yet another server just to filter emails. The load on the email server is relatively low, so it should be able to handle this task easily too.
  3. to R&D Xen's abilities. Heard so much about it, but never had a real reason to try it out.
  4. A means to easily maintain a server which can be replicated / brought up or down on any available server
So with dspam set-up as a relay (setting up dspam of course is a story on its own), the 'appliance' consists of:
  1. postfix for the smtp transport
  2. the dspam daemon
  3. mysql server running in the VM
  4. apache for its webui for training
  5. webmin for easy admin
  6. no X to conserve memory
i can now 'copy' this machine to any production server (whenever I get 'round to doing it).
Also one of these days, put in ClamAV which I hear is easy to integrate with postfix.

So the R&D server had to be upgraded from 512MB to 1GB RAM because after all GUI and stuff running I only had 100MB left. And this wasn't enough for a guest install of 256MB minimum. With the new 1GB limit, I could run 2 VMs easily, 3 if Im lucky.

Good thing memory is cheap. Bad thing is the R&D server is using the old SDRAM which is getting abit of a rarity nowadays and commands a 50% premium over DDR sticks.

Xen rocks. Its wonderful. Try it. No more uptime 0.06 for my physical servers from now on. They'll now have to work for their keep. Opportunities are endless in terms of consolidating the servers as well as keeping the VM images for safekeeping.

Well, the next Windows Server will be a hypervisor with the ability to run Win2003 and even RedHat.
Microsoft chose WinHEC to talk up its virtualisation software because Longhorn will not be available until next year. At that time the company will be playing catch-up with VMware's ESX Server and XenSource's Linux-based Xen Hypervisor which are both available now.
This for me is good news. At least now we can really think about consolidation and guaranteed uptime for IT services and thats very important.

yk.