- dovecot - dovecot.org

[Dovecot] RAID benchmarks
by Ethan Sommer 21 Nov '06

21 Nov '06

We (a small college with about 3000 active accounts) are currently in the process of moving from UW IMAP running on linux to dovecot running on a cluster of 3 or 4 new faster Linux machines. (Initially using perdition to split the load.) As we are building and designing the system, I'm attempting to take (or find) benchmarks everywhere I can in order to make informed decisions and so that when we need something faster we have something to compare it to. I've looked all over the Internet and I haven't seen very many good benchmarks running on recent hardware for things like this. Even simple things like how different raid levels perform with fast CPUs and really fast disks. We recently got the first of the cluster machines (which has the following specs: (from penguin computing) 2x 1.6ghz woodcrest (so 4 cores total) 2g ram (we may upgrade to more, depending on what we seem to need) 6x 15k SAS 73G hard drives. I've always read that RAID 10 is the RAID of choice for mail, because the checksums take time and whatnot, but on a system that fast I'm sure that's not an issue (which I could see from the cpu usage during benchmarks.) We were also wondering whether RAID6 would be a good option since it would give more redundancy. (raid6 allows 2 drive failures) All tests were run on ext3 with all 6 disks in the raid. Everything is using Linux software raid. I used bonnie++ to run the benchmarks, and here are the initial results we got: Output Input RAID "Per Chr" "Block" "Per Chr" "Block" RAID6 34628, 97983, 23316, 39077 RAID5 39559, 32715, 32036, 52231 RAID10 38816, 229062, 40645, 267418 I assume that mail running maildir (as we intend to do) is somewhere between writing one char at a time and writing huge blocks to fill 4g files. Since the Per Chr values seemed to have maxed out the CPU and we'll have 4 cores available, I tried the same thing running 4 copies of bonnie at once and adding the results. (I worked backwards and didn't bother with raid 6 for obvious reasons) Output Input RAID "Per Chr" "Block" "Per Chr" "Block" RAID5 37465, 37095, 102828, 174263 RAID10 111239, 128287, 93400, 230320 So, if our system is ever running full out, basically disk bound, it should be able to handle about 4X as many writes and at least as many reads using RAID10 than raid 5, and since raid 6 was pretty similar to raid 5 in the first tests, I assume it will be here too. I have the full bonnie results if anyone's interested. I also plan to come up with some basic benchmarks as we start to actually have dovecot working as we want it to. (Possibly using the macs in our labs and XGrid as a "client".. finally a use for that thing :) ) Do people have suggestions as to what to test for a primarily IMAP (+ a little POP) server? I was thinking of doing something similar to http://www.courier-mta.org/mbox-vs-maildir/ which selects a mail box, deletes and expunges a message, fetches a few messages, and then does some searches. Also, while I have the opportunity, are there any other benchmarks I should run? I suppose I could compare dovecot with mbox vs maildir, with indexing and without. Dovecot with indexing but the indexes deleted, etc. I could compare dovecot to uw imap. Anything else? I probably can't justify the time to get cyrus up and running. (I did that a few months ago when deciding which server to use...) Ethan Sommer -- -- Ethan Sommer Systems Administrator Gustavus Adolphus College 507-933-7042 sommere(a)gac.edu

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[Dovecot] rc14 and rc15 performance issues
by Jeff A. Earickson 21 Nov '06

21 Nov '06

Hi, I am stuck at rc13 because rc14 and rc15 have both failed to keep up with imap connections on my (slow old) system. I have the problem where if a lot of people check their email at once (like at the top of the hour) then my load goes way up and things slow to a crawl. My setup: Solaris 10 on an E220R, mbox format, imap and imaps only. I also use "login_process_per_connection = no". Any suggestions? Jeff Earickson Colby College

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[Dovecot] how to configure dovecot
by Hein Celliers 21 Nov '06

21 Nov '06

Hi all! I need some help....changing passwords....... Dovecot server, appears to cache the old credentials. It only discovers the change upon a restart. I need to know how to configure dovecot (dovecot-1.0-0.beta2.7) as not to cache the passwords. (Using fedora core 5) Thanks Hein Celliers

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Re: [Dovecot] Dovecot on Solaris
by Joseph Tam 21 Nov '06

21 Nov '06

> For those running Dovecot on Solaris, what are your positive/negative > experiences with building the software with CC vs. GCC? We are currently > letting ./configure find our gcc and build with it, but wondered if anyone > has any experience with Sun CC (does it even compile, for example). I once used StudioCC to compile dovecot to see if the problem I had was a compiler bug, but in general, I use gcc since a lot of software is tested against it. I don't use Studio unless performance is critical. >From what I know, IMAP performance is basically disk-memory bounded, so it might not be worth sweating over: use whatever gives you the least grief. Joseph Tam <tam(a)math.ubc.ca>

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[Dovecot] manageSIEVE implementation
by Brian G. Peterson 20 Nov '06

20 Nov '06

I found a thread from last year that suggested that a manageSIEVE (port 2000) implementation for dovecot-sieve doesn't exist yet. I assume that this is still true. Could somebody please provide a status on this? Thanks, - Brian

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Re: [Dovecot] Auth checking also the service
by Andrey Panin 20 Nov '06

20 Nov '06

On 322, 11 18, 2006 at 12:56:41 +0100, Alessandro Astarita wrote: > Alle 12:14, sabato 18 novembre 2006, Johannes Berg ha scritto: > > I don't see why it wouldn't be possible but haven't looked at the code. > > > > I wonder why you even need to distinguish between these though. Are we > > still in the days where encryption is a value-added service? :) > > I have to distinguish pop3/pop3s and imap/imaps because I need mailboxes with > ssl access only. It's a way to force users to do secure connection. :-) Please try attached patch. It adds %c variable which expands to "TLS" if connection is secure. > -- > Alessandro 'Asterix' Astarita <aleast(a)capri.it> > Capri Online S.r.l. http://www.caprionline.it/ > "Unix IS user friendly. It's just selective about who its friend are" > -- Andrey Panin | Linux and UNIX system administrator pazke(a)donpac.ru | PGP key: wwwkeys.pgp.net

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[Dovecot] BUG: passdb checkpassword {} and lastauth file
by Max A 20 Nov '06

20 Nov '06

(Repeat, because on the first message there was no reaction) Hi. If checkpassword interface is used for working with vpopmail, function vpopmail "Record time and ip of last auth attempt" (--enable-auth-logging option for configure) won't work - the file "lastauth" is created in Maildir, but does not contain ip-address. If I had correctly understood, dovecot woldn't have set a enviroment variable TCPREMOTEIP for vchkpw. If changes are made in auth/passdb-checkpassword.c (a patch in attachment), everything will work. Probably, the patch is incorrect and does not solve all problems, however the request is to pay attention to existence of the problem. Also it is possible, that a similar problem exists with other variables TCP UCSPI protocol (http://cr.yp.to/proto/ucspi-tcp.txt) P.S. If use the interface vpopmail instead of checkpassword, the file "lastauth" will not be created at all, that is a little bit inconvenient. ********************************** System: dovecot-1.0.rc10 vpopmail-5.4.17 ASP Linux Server II (RHEL3 clone) kernel 2.4.21-47.EL.aspsmp CPU architecture: x86 (IBM xSeries 336) Filesystem: ext3 ********************************** dovecot configuration: base_dir = /var/run/dovecot/ protocols = imap pop3 disable_plaintext_auth = no ssl_disable = yes login_greeting = Ready. first_valid_uid = 89 last_valid_uid = 89 first_valid_gid = 89 last_valid_gid = 89 protocol imap { listen = 81.26.136.8:144 mail_executable = /usr/local/libexec/dovecot/imap mail_plugins = quota imap_quota mail_plugin_dir = /usr/local/lib/dovecot/imap imap_client_workarounds = delay-newmail outlook-idle netscape-eoh tb-extra-mailbox-sep } protocol pop3 { listen = 81.26.136.8:112 login_executable = /usr/local/libexec/dovecot/pop3-login mail_executable = /usr/local/libexec/dovecot/pop3 pop3_uidl_format = %f mail_plugins = quota mail_plugin_dir = /usr/local/lib/dovecot/pop3 pop3_client_workarounds = outlook-no-nuls oe-ns-eoh } auth default { mechanisms = plain login passdb checkpassword { args = /var/qmail/vpopmail/bin/vchkpw } userdb prefetch { } user = root } dict { } plugin { quota = maildir } *************************************** dovecot configure options: ./configure \ --disable-ipv6 \ --prefix=/usr/local \ --sysconfdir=/etc/dovecot \ --without-passwd \ --without-passwd-file \ --without-shadow \ --without-pam \ --without-bsdauth \ --with-checkpassword \ --with-vpopmail \ --without-static-userdb \ --with-prefetch-userdb \ --without-sql \ --without-pgsql \ --without-mysql \ --without-sqlite \ --with-ssl=openssl \ --with-pop3d \ --without-deliver \ --with-storages=maildir \ --with-docs ***************************************** vpopmail configure options: ./configure \ --enable-auth-module=cdb \ --enable-logging=p \ --enable-md5-passwords \ --enable-make-seekable \ --enable-file-sync \ --enable-ip-alias-domains \ --enable-clear-passwd \ --disable-roaming-users \ --disable-learn-passwords \ --disable-passwd \ --enable-auth-logging diff -ur dovecot-1.0.rc10.orig/src/auth/passdb-checkpassword.c dovecot-1.0.rc10/src/auth/passdb-checkpassword.c --- dovecot-1.0.rc10.orig/src/auth/passdb-checkpassword.c 2006-08-22 06:37:56.000000000 +0400 +++ dovecot-1.0.rc10/src/auth/passdb-checkpassword.c 2006-10-17 16:47:09.000000000 +0400 @@ -226,6 +226,10 @@ env_put(t_strconcat("REMOTE_IP=", net_ip2addr(&request->remote_ip), NULL)); + env_put(t_strconcat("TCPREMOTEIP=", + net_ip2addr(&request->remote_ip), + NULL)); + } if (request->master_user != NULL) { env_put(t_strconcat("MASTER_USER=",

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[Dovecot] dovecot and ldap passwords.
by Mauro Sanna 20 Nov '06

20 Nov '06

Hallo. First of all I'm sorry for my bad english. I have a question about how dovecot use passwords. I have all my mail accounts in a ldap database. The user password are stored in form: {crypt}mypasswd. In dovecot-ldap.conf I have default_pass_scheme = CRYPT. All is working fine. The problem in the crypt scheme is that I can't have passwords more than 8 characters long. So I've tried to change the type of the ldap passwords in SSHA or SMD5, but in this way the users can't authenticate yourselfs. Dovecot doesn't understand SSHA or SMD5?

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[Dovecot] Problem with rc10
by Steven F Siirila 20 Nov '06

20 Nov '06

I just upgraded our test server from rc6 to rc10... ISSUE #1 I noticed that we no longer are getting two "From_" lines. However, the one that was good (had the original sender e-mail address) is now gone. The one with "dovecot.deliver" remains. I attempted to add "-d test" to the mailbox_command line in main.cf as follows: mailbox_command = /opt/dovecot/libexec/dovecot/deliver -d test and things turned ugly and caused Postfix to defer messages: Oct 17 16:31:50 hostname postfix/local[7230]: D14632C9C: to=<someuser@somehost>, relay=local, delay=3.6, delays=3/0.02/0/0.62, dsn=4.3.0, status=deferred (temporary failure) I removed the "-d test" from the Postfix main.cf and the problem went away. So, how do I fix the "From_" lines? ISSUE #2 After upgrading, messages cannot be moved from the INBOX to a folder. Thunderbird claims there was an internal error and to consule the server logs, but I see nothing in the dovecot logs that would indicate what's going on. For example, I attempted to move a message into my Trash folder which did not currently have any index files. Here is a Solaris truss output of that attempt: poll(0x000B4C98, 2, 999) = 0 poll(0x000B4C98, 2, 0) = 0 poll(0x000B4C98, 2, 999) = 1 read(0, " D O N E\r\n", 3323) = 6 write(1, " 2 8 O K I d l e c".., 23) = 23 read(0, 0x000BC5BB, 3317) Err#11 EAGAIN poll(0x000B4C98, 2, 675) = 1 read(0, " 3 0 u i d c o p y ".., 3317) = 27 stat64("/home/sfs/Trash", 0xFFBFF5C8) = 0 alarm(120) = 0 fcntl(6, F_SETLKW64, 0xFFBFF308) = 0 alarm(0) = 120 stat64("/home/sfs/Trash", 0xFFBFF640) = 0 mkdir("/home/sfs/.imap/Trash", 0770) Err#17 EEXIST stat64("/home/sfs/.imap/Trash", 0xFFBFF4C0) = 0 stat64("/home/sfs/Trash", 0xFFBFF4C0) = 0 time() = 1161122396 open64("/home/sfs/.imap/Trash/dovecot.index", O_RDWR) Err#2 ENOENT open64("/home/sfs/.imap/Trash/dovecot.index", O_RDWR) Err#2 ENOENT write(1, " 3 0 N O I n t e r n".., 96) = 96 poll(0x000B4C98, 2, 588) = 0 poll(0x000B4C98, 2, 0) = 0 poll(0x000B4C98, 2, 410) = 0 Someone else using a different IMAP client caused these errors to occur (this is even after I wiped all of their dovecot index files): Oct 17 16:43:11 earth.tc.umn.edu dovecot: IMAP(kor): Corrupted transaction log file /home/kor/.imap/INBOX/dovecot.index.log: invalid indexid (1161121145 != 1156185395) Oct 17 16:43:11 earth.tc.umn.edu dovecot: IMAP(kor): Corrupted transaction log file /home/kor/.imap/INBOX/dovecot.index.log: invalid new transaction log sequence (6 >= 6) Oct 17 16:47:09 earth.tc.umn.edu dovecot: IMAP(kor): Corrupted transaction log file /home/kor/.imap/INBOX/dovecot.index.log: invalid indexid (1161121145 != 1161120959) Oct 17 16:47:09 earth.tc.umn.edu dovecot: IMAP(kor): Corrupted transaction log file /home/kor/.imap/INBOX/dovecot.index.log: invalid new transaction log sequence (2 >= 2) Oct 17 17:05:59 earth.tc.umn.edu dovecot: IMAP(kor): Corrupted transaction log file /home/kor/.imap/INBOX/dovecot.index.log: invalid indexid (1161121145 != 1161120959) Oct 17 17:05:59 earth.tc.umn.edu dovecot: IMAP(kor): Corrupted transaction log file /home/kor/.imap/INBOX/dovecot.index.log: invalid new transaction log sequence (4 >= 4) Here are our non-standard dovecot.conf items: protocols = imap imaps pop3 pop3s shutdown_clients = no syslog_facility = local6 ssl_cert_file = /etc/opt/openssl/certs/dovecot.pem ssl_key_file = /etc/opt/openssl/private/dovecot.pem default_mail_env = mbox:~/:INBOX=/var/mail/%u # Default namespace namespace private { separator = / prefix = location = mbox:~/:INBOX=/var/mail/%u inbox = yes hidden = yes } mail_full_filesystem_access = yes first_valid_uid = 100 max_mail_processes = 8192 mbox_min_index_size = 128 imap_client_workarounds = delay-newmail outlook-idle tb-extra-mailbox-sep pop3_uidl_format = %08Xu%08Xv protocol lda { postmaster_address = postmaster(a)umn.edu mail_plugins = cmusieve } auth_verbose = yes auth_debug = yes auth default { passdb pam { args = session=yes * } } I am now backing out to rc6 for now... we never saw this behavior on rc6. -- Steven F. Siirila Office: Lind Hall, Room 130B Internet Services E-mail: sfs(a)umn.edu Office of Information Technology Voice: (612) 626-0244 University of Minnesota Fax: (612) 626-7593

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[Dovecot] Problems Creating Core Dumps
by Joseph D. Wagner 20 Nov '06

20 Nov '06

Dovecot 1.0.rc15 crashed on my FC4 server, but it didn't create a core dump. Upon further research, I found these lines tucked away in the /etc/rc.d/init.d/functions file: # make sure it doesn't core dump anywhere unless requested ulimit -S -c ${DAEMON_COREFILE_LIMIT:-0} >/dev/null 2>&1 The /etc/rc.d/init.d/functions file is a master file that is referenced by all of the init scripts, so I didn't want to change it. Instead, I created a file /etc/sysconfig/dovecot with the following line: DAEMON_COREFILE_LIMIT=unlimited If I'm reading the /etc/rc.d/init.d/functions file correctly, this should work, but my bash is rusty. I was hoping someone else could check my work. Joseph D. Wagner

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