[Dovecot] maildir in NFS

[Lev Butyrev]

How can I configure the dovecot for working with maildir's through NFS?

If I add option "index_mmap_invalidate = yes" (as in doc/nfs.t) then in log I 
have this message:

"Error: Error in configuration file /etc/dovecot.conf line 296: Unknown 
setting: index_mmap_invalidate"

If I try to get the mail without option "index_mmap_invalidate" then I have in 
log this message:

"Error: POP3(butyrev.lk): mail_index_lock_fd() failed with 
file /var/mail/sam-butyrev.lk/dovecot.index.log: No locks available dovecot: 
Error: POP3(butyrev.lk): mail_index_wait_lock_fd() failed with 
file /var/mail/sam-butyrev.lk/dovecot.index.log: No locks available dovecot: 
Error: POP3(butyrev.lk): Couldn't open INBOX: Internal error occured. Refer 
to server log for more information."

dovecot-stable-20050414