...

John, thanks for your answer, I think I'm looking for a hihg

performance

...

cluster with two pcs... Apache, Mailscanner/Postfix, mysqld and squid are going to run in this cluster..

Each of those apps has its own requirements for a shared workload

<cluster. frankly, I have no idea how a squid cluster could or would work.

webservers like apache are most frequently clustered by being put

behind

a load balancing router such as BigIP from F5. this is $$$$$$.

mysql has its own clustering support, I'm not very familiar with it. typically, these require shared storage.

not sure why you'd need to cluster a mail server other than high availability, this typically requires shared storage for the spool

files

and such.

I have no idea how you'd loadbalance cluster a squid cacheing proxy between two systems with discrete SATA drives. maybe if the squid

cache

was stored on a NFS server?

frankly, with that workload, and the hardware resources you described, you'd probably get the best performance by balancing the applications across the two systems. whichever app requires the most resource, put it on one, put the rest on the other. if the 'other' is overloaded, move another task to the first.

John, I'm reading now some stuff of clustering from internet, thanks for your opinion, let me ask you, (maybe a stupid question), which are the common applications used on cluster's systems? Web?

Regards, Israel