RLimitOpenFiles [ RLimitOpenFiles ["daemon"|"session"|"none"] soft-limit|"max" [hard-limit|"max"]]
1.2.1rc1 and later
RLimitOpenFiles takes from one to three parameters. The first parameter may be one of "daemon" (applies the limit only to the daemon process), "session" (applies the limit only to child processes handling each FTP session), or "none" (disables any possibly inherited limits). Note that if "daemon" is used, the directive may then only occur in the "server config" context. If none of these keywords are used, the limit is assumed to apply to both daemon and session processes. After any potential keyword, the resource limit must be set. The next parameter is also optional, and sets the maximum resource limit. Either limit parameter can be a number, or "max" to indicate to the server that the limit should be set to the maximum allowed by the operating system.
File resource limits are expressed in number of files per process.