September 2010 - dovecot

[Dovecot] LAYOUT=maildir++ under mbox?
by William Blunn 06 Sep '10

06 Sep '10

Whilst documenting LAYOUT=maildir++ under dbox, that got me thinking: Can we specify :LAYOUT=maildir++ with mbox? If I have it right, this should then remove the problem of not being able to have messages and mail subfolders in the same mail folder. So for example if we had mail location specified as: mail_location = mbox:~/mail:LAYOUT=maildir++ we would have files: ~/mail/inbox - file storing messages in INBOX ~/mail/.foo - file storing messages in mail folder "foo" ~/mail/.foo.bar - file storing messages in mail folder "foo/bar" and I think all of Dovecot's indexes would go under ~/mail/.imap Bill

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[Dovecot] extended search
by Daniel-Constantin Mierla 06 Sep '10

06 Sep '10

Hello, is it safe to use arg_new_human_date() from src/lib-storage/mail-search-register-human.c instead of arg_new_date() inside src/lib-storage/mail-search-register-imap.c? The benefit is ability to use interval based search rules, e.g., SINCE 2days. I run it for couple of days and looks fine, used for virtual folders. This kind of search I missed for usage on laptop - I have pretty huge inboxes, thunderbird was over 20% CPU all the time. I switched on using dovecot locally and thunderbird connected to it, my common searches (before: thunderbird's "save as folder" searches) are virtual folders. Everything works great, cpu usage is less than 1% (I have to say that I also moved many filtering rules (for sorting incoming messages to folders) from TB to be done by imapfilter, but the reason was mainly sorting flexibility and rescanning folders). If all is safe, would it be considered for addition in the future version? The patch is trivial, I can leave with patching every release, but I believe is a nice thing to have. Afaik, should not break IMAP SEARCH specs, being an extended version. An alternative would be to add 'X-' commands (e.g., X-SINCE 2days). Thanks, Daniel -- Daniel-Constantin Mierla http://www.asipto.com

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[Dovecot] Problems with zlib
by Andre 06 Sep '10

06 Sep '10

Sometimes I see lines like these in my log: 20100906 11:34:32 imap(username(a)domain.com): Panic: file istream-zlib.c: line 173 (i_stream_zlib_read): assertion failed: (zstream->high_pos == 0) 20100906 11:34:32 imap(username(a)domain.com): Error: Raw backtrace: /usr/lib/dovecot/libdovecot.so.0 [0x7f328d2244a2] -> /usr/lib/dovecot/libdovecot.so.0 [0x7f328d22450a] -> /usr/lib/dovecot/libdovecot.so.0(i_error+0) [0x7f328d2248b3] -> /usr/lib/dovecot/modules/lib20_zlib_plugin.so [0x7f328be444fc] -> /usr/lib/dovecot/libdovecot.so.0(i_stream_read+0x6b) [0x7f328d22a10b] -> /usr/lib/dovecot/libdovecot.so.0(i_stream_read_data+0x4d) [0x7f328d22a3fd] -> /usr/lib/dovecot/libdovecot.so.0 [0x7f328d21476e] -> /usr/lib/dovecot/libdovecot.so.0 [0x7f328d214cbe] -> /usr/lib/dovecot/libdovecot.so.0(message_parser_parse_next_block+0x29) [0x7f328d2148c9] -> /usr/lib/dovecot/libdovecot.so.0(message_parser_parse_body+0x23) [0x7f328d214a43] -> /usr/lib/dovecot/libdovecot-storage.so.0 [0x7f328d4cb72f] -> /usr/lib/dovecot/libdovecot-storage.so.0 [0x7f328d4cb84a] -> /usr/lib/dovecot/libdovecot-storage.so.0(index_mail_get_special+0x3dc) [0x7f328d4cc99c] -> /usr/lib/dovecot/libdovecot-storage.so.0 [0x7f328d4dd86d] -> dovecot/imap [username(a)domain.com 192.168.4.253 UID] [0x41256a] -> dovecot/imap [username(a)domain.com 192.168.4.253 UID](imap_fetch_more+0x16c) [0x412b0c] -> dovecot/imap [username(a)domain.com 192.168.4.253 UID](cmd_fetch+0x3fa) [0x40acea] -> dovecot/imap [username(a)domain.com 192.168.4.253 UID] [0x41031c] -> dovecot/imap [username(a)domain.com 192.168.4.253 UID] [0x4103cd] -> dovecot/imap [username(a)domain.com 192.168.4.253 UID](client_handle_input+0x45) [0x410545] -> dovecot/imap [username(a)domain.com 192.168.4.253 UID](client_input+0x62) [0x410f72] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0xcb) [0x7f328d22f3ab] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_run+0x18) [0x7f328d22e4c8] -> /usr/lib/dovecot/libdovecot.so.0(master_service_run+0x13) [0x7f328d21dd63] -> dovecot/imap [username(a)domain.com 192.168.4.253 UID](main+0x281) [0x419201] -> /lib/libc.so.6(__libc_start_main+0xe6) [0x7f328caa81a6] -> dovecot/imap [username(a)domain.com 192.168.4.253 UID] [0x408bd9] Here is the backtrace: [New process 11474] #0 0x00007f328cabbed5 in raise () from /lib/libc.so.6 (gdb) bt #0 0x00007f328cabbed5 in raise () from /lib/libc.so.6 #1 0x00007f328cabd3f3 in abort () from /lib/libc.so.6 #2 0x00007f328d2244b5 in ?? () from /usr/lib/dovecot/libdovecot.so.0 #3 0x00007f328d22450a in ?? () from /usr/lib/dovecot/libdovecot.so.0 #4 0x00007f328d2248b3 in i_panic () from /usr/lib/dovecot/libdovecot.so.0 #5 0x00007f328be444fc in ?? () from /usr/lib/dovecot/modules/lib20_zlib_plugin.so #6 0x00007f328d22a10b in i_stream_read () from /usr/lib/dovecot/libdovecot.so.0 #7 0x00007f328d22a3fd in i_stream_read_data () from /usr/lib/dovecot/libdovecot.so.0 #8 0x00007f328d21476e in ?? () from /usr/lib/dovecot/libdovecot.so.0 #9 0x00007f328d214cbe in ?? () from /usr/lib/dovecot/libdovecot.so.0 #10 0x00007f328d2148c9 in message_parser_parse_next_block () from /usr/lib/dovecot/libdovecot.so.0 #11 0x00007f328d214a43 in message_parser_parse_body () from /usr/lib/dovecot/libdovecot.so.0 #12 0x00007f328d4cb72f in ?? () from /usr/lib/dovecot/libdovecot-storage.so.0 #13 0x00007f328d4cb84a in ?? () from /usr/lib/dovecot/libdovecot-storage.so.0 #14 0x00007f328d4cc99c in index_mail_get_special () from /usr/lib/dovecot/libdovecot-storage.so.0 #15 0x00007f328d4dd86d in ?? () from /usr/lib/dovecot/libdovecot-storage.so.0 #16 0x000000000041256a in ?? () #17 0x0000000000412b0c in imap_fetch_more () #18 0x000000000040acea in cmd_fetch () #19 0x000000000041031c in ?? () #20 0x00000000004103cd in ?? () #21 0x0000000000410545 in client_handle_input () #22 0x0000000000410f72 in client_input () #23 0x00007f328d22f3ab in io_loop_handler_run () from /usr/lib/dovecot/libdovecot.so.0 #24 0x00007f328d22e4c8 in io_loop_run () from /usr/lib/dovecot/libdovecot.so.0 #25 0x00007f328d21dd63 in master_service_run () from /usr/lib/dovecot/libdovecot.so.0 #26 0x0000000000419201 in main () here is the relevant plugin section: plugin { zlib_save = gz zlib_save_level = 6 } What can I do to investigate deeper? TIA Andre

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Re: [Dovecot] dovecot Digest, Vol 89, Issue 27
by Alan Brown 06 Sep '10

06 Sep '10

> > Timo Sirainen <tss(a)iki.fi> Wrote: > > > > > On Mon, 2010-09-06 at 14:26 +0100, Alan Brown wrote: > > > > Is there any way of enforcing a Maildir per-folder message limit in > > > > Dovecot? > > > > > No. > > > > Would you consider it as a feature request? > What if you just create a script that automatically archives older mails to <box>/archive/yyyy-mm mailboxes when number of messages in a mailbox increases too high for too long? Or something like that. I'm looking at doing that anyway, however it would be much easier to train the users if the server says "folder full"

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Re: [Dovecot] dovecot Digest, Vol 89, Issue 25
by Alan Brown 06 Sep '10

06 Sep '10

Timo Sirainen <tss(a)iki.fi> Wrote: > On Mon, 2010-09-06 at 14:26 +0100, Alan Brown wrote: > > Is there any way of enforcing a Maildir per-folder message limit in > > Dovecot? > No. Would you consider it as a feature request? > > We're finding major performance hits once a threshold of files/directory > > is exceeded. This applies across all common filesystems with the > > threshold differing depending on the FS. GFS2 pretty much _STOPS_ for 10 > > minutes when users put 65k+ messages in one folder... > mdbox would probably work nicely. :) Yes, it probably would, however I have several layers of resistance to get past in order to implement that (ie, up to 2 years to get approval to switch to dbox) > > I'm currently running 1.1.20 but looking to update (RHEL5 cluster > > installation) > With v1.2+ you could also try maildir_very_dirty_syncs=yes That won't help much for initial directory opens, which is where most of the pain is. Past that point, the index of ~/Maildir/.folder/cur is mostly cached until you hit about 16,000 messages(files) on GFS2 and some people are insisting on 32k+ files in one folder with the odd few trying 65k or more (I'm surprised their clients don't break). For info sake: we have Dovecot running on a pair of dedicated dual E5530 (quad-core X86 1300MHZ FSB cpu) servers (RH cluster+GFS2) with 24Gb RAM apiece and ~2TB of 8Gb/s san-attached storage available. There are only ~250 accounts but there's around 600Gb in the maildir folder areas and another 300Gb in a separate dedicated inbox area - and I believe there's another 1TB of stuff in client local folders we're trying to pull back to the servers in order to simplify backups. Even with this kind of horsepower available, over-large folders can render the setup completely unresponsive for minutes at a time. I know this is a case of "work smarter, not harder", but I'm facing major delays until we're able to change the on-disk storage format. Alan

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Re: [Dovecot] dovecot Digest, Vol 89, Issue 26
by Alan Brown 06 Sep '10

06 Sep '10

Timo Sirainen <tss(a)iki.fi> Wrote: >On Mon, 2010-09-06 at 12:37 +0100, William Blunn wrote: > > Whilst documenting LAYOUT=maildir++ under dbox, that got me thinking: > > > > Can we specify :LAYOUT=maildir++ with mbox? > Yes, ever since LAYOUT was added. > > If I have it right, this should then remove the problem of not being > > able to have messages and mail subfolders in the same mail folder. > Yes. Also it might be possible to use DIRNAME with LAYOUT=fs to solve > that problem, but I'm less sure about that. I anyway doubt most mbox > users want to switch to a whole new layout. Mbox users might not, but Maildir or dbox users might want to, especially if users have a lot of folders (One of mine has ~2500) Directories definitely get slower to list with more files/subdirectories in them and there are knee points beyond which they get substantially slower (Where the knee is depends on the type of FS but it's usually a power of 2)

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[Dovecot] mdbox: Cannot create subfolder called "dbox-Mails" (2.0beta5)
by William Blunn 06 Sep '10

06 Sep '10

I am trying out "mdbox" under Dovecot 2.0beta5. Looking in the "mailboxes" directory under the mdbox storage root ("~/dbox" in my case), I can see that the mail folders are mapped into filesystem directories. But Dovecot seems to put all the message list information ("dovecot.index.cache", "dovecot.index.log") for any given mail folder into a directory called "dbox-Mails"... But this directory name exists in the same namespace as that used for mail subfolders... So this means we cannot create a mail subfolder whose name is "dbox-Mails"! I concede that this eventuality may be unlikely, but when designing in a green field, surely we should avoid such obvious pitfalls? Surely we would want to make it so that these objects exist in different namespaces, so that mail folders can be created with any name? So perhaps the directory "dbox-Mails" should use a character in its name which could not be used in mail folder names. Or mail folder names could have a non-identity mapping into directory names such that the directory name can never be "dbox-Mails". Regards, Bill

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[Dovecot] Specify auth service for protocols
by Lukas Garberg 06 Sep '10

06 Sep '10

Hi all, I'm building a mail system where two machines are functioning both as POP3/IMAP-proxy (using dovecot 1.2.12) and SMTP-server with authentication for outgoing mail. The SMTP-server is postfix with dovecot SASL as authentication backend. User credentials for SMTP auth as well as the mapping from account to final server for the proxy is stored in a MySQL-database which dovecot queries. As I want the POP3/IMAP-proxy to accept any username and password (as the final POP3/IMAP server takes care of the authentication) the passdb SQL query has the statements "NULL AS password, 'Y' AS nopassword, 'Y' AS proxy" added to the query. As these additions cannot be used in the SQL query for the auth service used by postfix (as users would be able to authenticate with any password) I have defined a second auth service (auth postfix { ... }) in dovecot.conf which is slightly different; it returns the password hash instead of NULL as password and skips the proxy and nopasswd part. This works fine on one server, but on the other one the auth services get mixed up and the service defined for postfix (missing password and proxy stuff) is used by the POP3 and IMAP services and vice versa, which breaks the proxying. I've been trying my best to find any difference between the configuration of the two machines, but without result. The configurations are simply copies of each other. So, to finally arrive at my question: Is there any way to specify which authentication service is to be used by each protocol in dovecot.conf? Or is the solution instead to rewrite the passdb-query to take the service into account and return 'Y' AS proxy when the service is postfix and 'N' AS proxy when the service is POP3 or IMAP as I then would be able to use only one authentication backend? Sorry for the lengthy post and thank you in advance! Regards, Lukas Garberg

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[Dovecot] notification plugin
by Wolfgang Rosenauer 06 Sep '10

06 Sep '10

Hi, I'm pretty new to dovecot's codebase and trying to write a plugin which performs certain plugins if new mail arrives in a user's mailbox. I saw the mail-log plugin and was playing around with it but it seems to not create events if new mails arrive but only if mail are copied or saved from an IMAP connection. Are there any hooks I can base my plugin on to get events in the above case? Any pointers? Thanks, Wolfgang

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[Dovecot] Quotas - per folder message limits?
by Alan Brown 06 Sep '10

06 Sep '10

Is there any way of enforcing a Maildir per-folder message limit in Dovecot? We're finding major performance hits once a threshold of files/directory is exceeded. This applies across all common filesystems with the threshold differing depending on the FS. GFS2 pretty much _STOPS_ for 10 minutes when users put 65k+ messages in one folder... I'm currently running 1.1.20 but looking to update (RHEL5 cluster installation)

2 1