I've been reading a few topics about VPS here and it left me wondering if it is really the case that on a Virtuozzo VPS some programs, like Apache, are shared amongst accounts. That would mean I can't run my own version of Apache in case I want a different version than the system default? Anyone know for what other programs this counts?
The thing with apache on virtuozzo, no. It can be setup like this however, can also not be. Virtuozzo is better than UML, but it is VERY expensive. Virtuozzo allows you to run 1 control panel binary for all the accounts. Then you buy the smaller cPanel license and you dont pay $19.99/mo. but rather $5-$10/mo. If you have the money, go with Virtuozzo.
By default they are shared but I've had no problems compiling and starting my own. In fact I had to compile apache 1.3.31 to work with PHP5 because apache 2.0.47 that came by default kept segfaulting whenever I called up a php5 script. I think it's an issue with RH Enterprise AS3 because I've had no problems running apache 2.0.47 and php5 at home on RH 8.
The thing you have to remember is this: If you make your own binary of say apache, mysql, postgres then make sure you update the script that starts/shutdowns it in /etc/init.d to reflect your new binary location. Since /etc/init.d/httpd by default is trying to start apache 2.0.47 then it wil start it the next time your machine is rebooted if you don't change it. So either update that to point to the new binary or disable it and put in a quick line in /etc/rc.local to start yours.