cannot pass phase fill

hi all,

I try with polymix-4 to test my squid cache with L4 switch, I have 2 cache
servers in my cache pool, my test server and client run on FC4
2.6.13-1.1532_FC4 with 2GB Ram for client and 1 GB Ram for server1, test
duration: 4 hours but i cannot pass the phase fill, my test server is still
alive but my client halt, my client hdd read continuously, and and server
will be timeout! could you have me to solve this problem?

Thanks in adv,

@ hoai anh