vsftpd error: 500 OOPS: setuid

Question

I sometimes get an error when I want to login via ftp. The error is 500 OOPS: setuid. I can't figure out why this happens sometimes, but sometimes it doesn't. I've se the limit of processes per user to unlimited, but this still happens. I'm running Fedora Core 10.

Answer 1

From the vsftpd wiki:

I'm getting: 500 OOPS: setuid - Why?

setuid(2) sets the user identity for a process. If the user in question has run out of processes -- ulimit(1) -- this will fail, and vsftpd will return said error.

This behaviour is most common seen on embedded devices, where the number of processes a user is allowed to spawn is actually limited. On most common-place Linux distros this is set unlimited.

You can verify this by checking under what username vsftpd is running with ps -ef | grep ftp.

Then log in as this user with the su - [username, for example root] command, and check the limit for the number of processes with ulimit -u.

On my CentOS machine the root account was limited to 2047 processes.
Raise this number if needed with ulimit -u [number of processes, for example 5000], or useulimited -u unlimited for an unlimited number of processes.