Re: question about modern lamp clustering technique [long]
Hi Wojciech. You asked for opinions here is mine but I think there might be a possibility I misunderstood your question all together.
On Thursday 21 October 2010 19:48:37 Wojciech Ziniewicz wrote:
> So provided that you have 2 servers ,each capable of 4 strong VMs
> (6GBram/2cpu) - how would You divide this lil'farm to have following
> services : shared mysql database , shared postgresql database, shared
> static content server, non-shared dynamic content (app) server with
> php/ruby/whatever workers
I would use DRBD for failover, run everything on one machine and let the second one just keep up in case the first one fails. Of course it's a waste but you don't want a single point of failure. Actually, if money is an issue (usually is), get a massive primary machine and a not so fast but bareable secondary as it will only be loaded heavily while your fixing the primary.
For reasons of caching by the OS, MySQL, Apache, PHP it's better to have NO virtualisation IMHO because it just duplicates those caches. I don't know - but I didn't really understand why you would use virtualisation.