So I have finshed deploying vicidial with asterisk 1.4.11. The system went live 2 weeks ago.
My server hardware:
Athlon X2 5600+
4Gb memory
2x400G SATA2 HDs in RAID0 for the recordings
Digium TE120P connected to an E1 with 12 channels
CentOS5 with lates patches
~15 campaigns, all calls recorded
Agent side:
Low-cost linux PCs running Fedora 7
Bugetone BT-200 SIP phones
The first day of operation went fine, but we had only 3-4 agents logged on at any time. Average load was between 1 and 2, rarely spiking above 2.
The second day we had full house (7 agents). Now this was the time when problems started to appear. Average load went above 2 with spikes up to 4+. Asterisk crashed. And crashed again after 20 mins... To reduce load I switched off the recording conversion (now the recordings are converted to mp3 during the night). We worked with 6 agents for the rest of the day.
During the second night I made some changes. To reduce load I set up a 500M RAM drive for the recordings and a cronjob to move all these recordings to HD every 1 hour. Got 7 agents onto the system and everything went just fine. Average load stayed below 2 and didn't have any problems since the introduction of the RAM drive.
Couple of more points about this specific install.
- this server is used by the rest of the office (~12 SIP extensions inbound/outbound calls)
- eaccelerator is not installed yet (as php version is 5.1.x and eaccelerator is only beta for php 5.1)
So the next thing will be to either move the webserver or the db server onto a different machine, so more agents could use the system (though this is not a priority yet as since the introduction of vicidial agent productivity went through the root!

)
If anybody has any questions just ask!