I wanted to store images of client PC's on our server. This would involve
copying from each client a single file of between 2 Gb and 10Gb working
over a 100Mb or 1Gb connection. On trying the first such copy, I found it
immediately brought service to all other users to a halt.

Packet receive buffers is 1000 and instantly there were 1000-1020 current
disk requests where normally it is about 6-10.

OK, the server has only 1Gb of memory but 4 processor cores, two SCSI
drives in a raid mirror and normally serves 40-50 users with complete
satisfaction at less than 2% CPU utilisation.

It just seems odd to me that a single user can, by copying a large file,
so monopolise the server as to bring everyone else to a standstill. Is
this behaviour normal?