- See also SPEED Update 2nd Nov 2001 ftp.redhat.com ran vsftpd for the RedHat 7.2 release. vsftpd achieved 4,000 concurrent users on a single machine with 1Gb RAM. Even with this insane user count, bandwidth remained totally saturated. The user count could have been higher, but the machine ran out of processes. -- Below are some quick benchmark figures vs. wu-ftpd. This is an untuned BETA version of vsftpd (0.0.10) The executive summary is that wu-ftpd got a thorough thrashing. The most telling statistic is wu-ftpd typically failing to sustain 400 users, whereas vsftpd copes with 1000 with room to spare. A 2.2.x kernel was used. A 2.4.x kernel should make vsftpd look even better relative to wu-ftpd thanks to the sendfile() boosts in 2.4.x. A 2.4.x kernel with zerocopy should be amazing. Many thanks to Andrew Anderson <andrew@redhat.com> -- Here's some benchmarks that I did on vsftpd vs. wu-ftpd. The tests were run with "dkftpbench -hftpserver -n500 -t600 -f/pub/dkftp/<file>". The attached file are the summary output with time to reach the steady-state condition. The interesting things I noticed are: - In the raw test results, vsftpd had a much higher peak on the x10k.dat transfer run than wu-ftpd did. Wu-ftpd peaked at ~150 connections and bled down to ~130 connections, while vsftpd peaked at ~400 connections and bled down to ~160 connections. I tend to believe the peaks more than the final steady-state that dkftpbench reports, though. - For the other tests, our wu-ftpd setup was limited to 400 connections, but in about half of the x100k/x1000k runs could not even sustain 400 connections, while vsftpd handled 500 easily on those runs. - During the peak runs at x10k, the machine load with vsftpd looked like this (I don't have this data still for the wu-ftpd runs): 01:01:00 AM all 4.92 0.00 21.23 73.85 03:31:00 AM all 4.89 0.00 19.53 75.58 05:11:00 AM all 4.19 0.00 16.89 78.92 07:01:00 AM all 5.61 0.00 22.47 71.92 The steady-state loads were more in the 3-5% user, 10-15% system. For the x100/x1000 loads with vsftpd, the system load looked like this: x100k.dat: 09:01:00 AM all 2.27 0.00 9.79 87.94 x1000k.dat: 11:01:00 AM all 0.42 0.00 5.75 93.83 Not bad -- 500 concurrent users for ~7% system load. - Just for kicks I ran the x1000k test with 1000 users. At peak load: X1000k.dat with 1000 users: 04:41:00 PM all 1.23 0.00 46.59 52.18 Based on what I'm seeing, it looks like if a server had enough bandwidth, it could indeed sustain ~2000 users with the current 2 process model that's implemented in vsftpd. I did notice that dkftpbench slowed down the connection rate after 800 connections. I'm not sure if that was a dkftpbench issue, or if I ran into something other limit.