Hello, Dovecot documentation states that the "random redirects to multiple servers" NFS solution is to be avoided and I'm investigation the actual risks of it and a way to put it to test.
I'm running dovecot-1.2.6 with Maildir (indexes, mailboxes and control files are all on NFS) and I'm using procmail instead of deliver as the LDA. 1. Documentation says : "Dovecot locks the maildir while doing modifications to it or while looking for new messages in it" and then mention the "dovecot-uidlist.lock" dotlock file. a) if that file fcntl'ed in addition (i.e. dotlocked + fcntled or just dotlocked) ? b) is that file THE way to lock the Maildir mentionned above or is it just something else used only for updating that particular file (i.e. is Maildir locked in some way + dovecot-uidlist.lock created or just dovecot-uidlist.lock created) ? 2. Documentation says : "NFS caching is a big problem when multiple computers are accessing the same mailbox simultaneously" I guess it's because of the dotlocks files and not fcntl locking ? Is there anything else than dovecot-uidlist which is dotlocked ? If yes, is it dotlocked only or dotlocked and fcntled ? 3. Documentation says : "Dovecot v1.1 flushes NFS caches when needed if you set mail_nfs_storage=yes" How can a program flush the NFS caches ? By which (system) call ? 4. Documentation says : "Besides the NFS cache problems described above, mailbox contents can't be cached as well in the memory either." Is it about in-memory indexes or part of indexes loaded into memory ? 5. How can I torture-test concurrent access to the same mailbox through 2 dovecot servers ? I don't see imaptest.c anymore on http://dovecot.org/tools but I see 2 nfs_test ? Is there some command line options I should use ? 6. when and why can a random redirect to multiple server can cause mailbox corruption ? On flags only or on content as well ? Thanks -- Thomas Hummel | Institut Pasteur <hum...@pasteur.fr> | Pôle informatique - systèmes et réseau