general load balancing issues

[Bogdan TARU]

	Dear hackers,

 Up until now, I had a setup with 4-5 webservers, one 'main' server on
 which all the changes to the websites were done, and the rest which
 were rsync-ing the web repository to the local drives. The content is
 either static or dynamic (PHP). Of course, I was load balancing (DNS
 round-robin) only the statical domains, and the ones involving PHP
 scripts which fetched all the informations from a database. The
 domains which involved PHP sessions were left on the 'main' server.

 Right now I am considering a setup with one common NFS repository for
 the configuration files, Apache binaries, Web content and temp
 directory for PHP, NFS resource which will be mounted on all the
 'front' webservers. I am wondering, though, if I will be able (by
 having one common temp directory for PHP) to load-balance the domains
 involving sessions: will the sessions be lost when connsecutive hits
 go to different webservers, or not? 

 I will also be interested in finding out more opinions about this
 sort of setup (interested in what are the pitfalls of the common NFS
 repository) from the people who already got it implemented.

 Thank you,
 bogdan