load balance

[ObiVan]

Hello,

I know that we have a "load balance" between file servers, which means if we have for example 2 servers than one file is uploaded on one server and another is uploaded on another server... and if one of them is down than all files are going to another server and so....

But the question is, is there any way to load balance the server which is running a script ? sometimes we need update the server and/or restart it etc... so it would be nice to have an option to load balance the script, is this possible ? if yes how ?

I know that this trick can be done via DNS server, but what about users created on one of the servers running a script if this server fails than user will access the another server but than the user will get a problems with the account because it does not exist...

So, any good idea how to load balance the server running a script ?

Thank You