[Dovecot] "pipe() failed: Too many open files"

[peter]

I am getting random disconnects from my imap session, dificulties to
revconnect, very sluggish behaviour when changing between mail folders
also frequent and rapidly repititive messages on te client "mailserver
x.x.x.x is not a imap4 server"

I am running dovecot 1.0.rc2 from ports on OpenBSD 4.0 on a PIII, 500MHz
512MB

My set up is very small - a webserver with a single imap account on it
for myself and my wife and a pop3 account for a printserver. The clients
are both Thunderbird on Linux (Ubuntu7.04 and Ubuntu 6.06

I have overall maybe 6000 mails distributed over all folders.

The maillog file looks like this:

Aug 31 20:51:44 apache dovecot: imap-login: Login: user=<my-login>,
method=plain, rip=y.y.y.y, lip=x.x.x.x, TLS
Aug 31 20:51:57 apache dovecot: pipe() failed: Too many open files
Aug 31 20:52:22 apache dovecot: imap-login: Disconnected: Inactivity:
rip=y.y.y.y, lip=x.x.x.x, TLS
Aug 31 20:52:57 apache dovecot: pipe() failed: Too many open files
Aug 31 20:52:57 apache dovecot: imap-login: Disconnected: Inactivity:
rip=y.y.y.y, lip=x.x.x.x, TLS
Aug 31 20:53:33 apache last message repeated 3 times
Aug 31 20:53:57 apache dovecot: pipe() failed: Too many open files
Aug 31 20:54:57 apache dovecot: pipe() failed: Too many open files
Aug 31 20:55:03 apache dovecot: IMAP(my-login): Disconnected: Logged out
Aug 31 20:55:52 apache dovecot: imap-login: Disconnected: Inactivity:
rip=y.y.y.z, lip=x.x.x.x, TLS
Aug 31 20:55:57 apache dovecot: pipe() failed: Too many open files
Aug 31 20:56:15 apache dovecot: imap-login: Disconnected: Inactivity:
rip=y.y.y.y, lip=x.x.x.x, TLS
Aug 31 20:56:30 apache last message repeated 3 times
Aug 31 20:56:57 apache dovecot: pipe() failed: Too many open files
Aug 31 20:56:57 apache dovecot: imap-login: Disconnected: Inactivity:
rip=y.y.y.y, lip=x.x.x.x, TLS
Aug 31 20:57:57 apache dovecot: pipe() failed: Too many open files
Aug 31 20:58:57 apache dovecot: pipe() failed: Too many open files
Aug 31 21:00:57 apache last message repeated 2 times
Aug 31 21:03:57 apache last message repeated 3 times


My dovecot -n looks like this:

# /etc/dovecot.conf
base_dir: /var/dovecot/
protocols: pop3 pop3s imap imaps
ssl_cert_file: /etc/ssl/dovecotcert.pem
disable_plaintext_auth: no
login_dir: /var/dovecot/login
login_executable(default): /usr/local/libexec/dovecot/imap-login
login_executable(imap): /usr/local/libexec/dovecot/imap-login
login_executable(pop3): /usr/local/libexec/dovecot/pop3-login
login_user: _dovecot
default_mail_env: maildir:%h/Maildir/
mbox_write_locks: fcntl
mail_executable(default): /usr/local/libexec/dovecot/imap
mail_executable(imap): /usr/local/libexec/dovecot/imap
mail_executable(pop3): /usr/local/libexec/dovecot/pop3
mail_plugin_dir(default): /usr/local/lib/dovecot/imap
mail_plugin_dir(imap): /usr/local/lib/dovecot/imap
mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3
imap_client_workarounds(default): delay-newmail outlook-idle
netscape-eoh tb-extra-mailbox-sep
imap_client_workarounds(imap): delay-newmail outlook-idle netscape-eoh
tb-extra-mailbox-sep
imap_client_workarounds(pop3): outlook-idle
pop3_uidl_format(default):
pop3_uidl_format(imap):
pop3_uidl_format(pop3): %08Xu%08Xv
pop3_client_workarounds(default):
pop3_client_workarounds(imap):
pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh
auth default:
  passdb:
    driver: passwd
  userdb:
    driver: passwd


What can I do?

Thanks a loy!