Posts Tagged ‘cdb’

Qmail’s Voodoo spells and magics ! Workarounds to some common problems, QMAIL HELL!

Friday, October 2nd, 2009

Reading Time: 3minutes

It's one of this days, when you'd wish to be dead and never born ever!

I experienced terrible problems with Qmail once AGAIN!

Most of the qmail administrators out there are probably aware, Everytime qmail stops working it's like

walking in a dark room without a light torch before you fix it up.

To fix a broken qmail your only friend could be patience. It's fucking insane seriously I more and more start hating qmail when it's broken.

I've experienced the following error messages today on our corporate qmail:

delivery xx: failure: Sorry._Although_I'm_listed_as_a_best-preference_MX_or_A_for_that_host,/it_isn't_in_my_control/locals_file,_so_I_don't_treat_it_as_local.

as well as:

delivery 232: deferral: Sorry,_I_wasn't_able_to_establish_an_SMTP_connection._(#4.4.1)/

A lot of this junk filled the qmail logs. I still am not completely sure the exact reasons

what caused the problems. However I fixed the situation tweakening some of the common

qmail and vpopmail configuration files and respectively their cdb files.

Here is the list of files I got to rebuild and the things I've did to resolve the qmail issues:

cd /home/vpopmail/domains;
for i in *; do echo +$i-:$i:89:89:/home/vpopmail/domains/$i:-:: >>assign; done
# backup old assign file just in case something goes wrong
cp -rpf /var/qmail/users/assign /var/qmail/users/assign.bak
mv assign /var/qmail/users/assign

# backup virtualdomains list file
cp -rpf /var/qmail/control/virtualdomains /var/qmail/control/virtualdomains.bak
for i in *; do echo $i:$i >>virtualdomains; done
mv virtualdomains /var/qmail/control/

# Make sure your /var/qmail/control/rcpthosts contains all the vpopmail domains
# backup rcpthosts for laters
cp -rpf /var/qmail/control/rcpthosts /var/qmail/control/rcpthosts.bak
for i in *; do echo $i >>rcpthosts; done
cp -rpf rcpthosts /var/qmail/control/
# backup morercpthosts
cp -rpf morercpthosts /var/qmail/control/morercpthosts.bak
# overwrite the old morercpthosts
# in my case morercpthosts was missing all the vpopmail virtual domains
# thus the domains missing the file wasn't able to receive mail
cp -rpf rcpthosts /var/qmail/control/morercpthosts

# Another problem if you're using qmail check user patch might be in /var/qmail/users/recipients
# Thus rebuilding the recipients file is a good idea.
# Rebuilding it might be done through qmail-vpopmail2recipients script
# the script has a bug the last if statement, where two if's have to be commented to make it wokring
# Below I'll put a link to a working version of the qmail-vpopmail2-recipients script

# Another possible problem could be in /var/qmail/users/cdb
# Therefore it might be a good idea to rebuild it with
# Another thing to do is to rebuild the /var/qmail/control/morercpthosts.cdb file with the command
# Other things I did was
# to assure myself that /var/qmail/control/me contains my mail server host name
# /var/qmail/control/locals should contain "localhost" as well as the FQDN (Fully Qualified Domain Name) (e.g. your domain name)

# Also I checked my /etc/tcp.smtp and assured myself everything is correct there.
# After which I executed
qmailctl cdb
# That rebuilded my /etc/tcp.smtp.cdb file
# Well that was mostly what I did to fix my problems.
# Another think that might be a good idea is to try
cd /home/vpopmail/domains;
for i in *; do /home/vpopmail/bin/vdominfo $i; done
# If you observe some domain's domain info cannot be shown
# then that might be due to some problem with your vpopmail
# It might be a good idea to check your
# qmail-showctl is a handy diagnosis qmail tool
# While looking over the command output
# I had to make sure my cdb files are "Modified Recently"
# and my virtualdomains are all showing up
# THat's mostly what fixed qmail for me
# Next I executed
qmailctl stop; sleep 10; qmailctl start
# that restarted my qmail
# However qmail doesn't always start logging to /var/log/qmail directory right away
# after restart
# SOmetimes the qmail server needs a couple of restarts before it starts serving mail
# Thus restarting it is always full of uncertancies and a lot of broken nerves!

I love qmail it absolutely works brilliant as long as it works, quite often

if you do even minor changes that usually means a broken qmail and qmail hell again!

I truly hope this post could be helpful to somebody out there

Here is a link to a working version of qmail-vpopmail2-recipients

Fix to mail forwarding error “Received-SPF: none ( domain at maildomain does not designate permitted sender hosts)

Tuesday, October 18th, 2011

Reading Time: < 1minute
I’m Configuring a new Exim server to relay / forward mail via a remote Qmail SMTP server
Even though I configured properly the exim to forward via my relaying mail server with host, still the mail forwarding from the Exim -> Qmail failed to work out with an error:

Fix to mail forwarding error "Received-SPF: none ( domain at maildomain does not designate permitted sender hosts)

I pondered for a while on what might be causing this “mysterous” error just to realize I forgot to add the IP address of my Exim mail server in the Qmail relay server

To solve the error I had to add in /etc/tcp.smtp on my Qmail server a record for my Exim server IP address xx.xx.xx.xx, like so:

debian-server:~# echo 'xx.xx.xx.xx:allow,RELAYCLIENT="",QS_SPAMASSASSIN="0"' >> /etc/tcp.smtp

The QS_SPAMASSASSIN=”0″ as you might have guessed instructs Qmail not to check the received mails originating from IP xx.xx.xx.xx with spamassassin.

Finally on the Qmail server to load up the new tcp.smtp settings I had to rebuild /etc/tcp.smtp.cdb and restart qmail :

– reload qmail cdb

linux-server:/var/qmail# qmailctl cdb
Reloaded /etc/tcp.smtp.
- restart qmail

linux-server:/var/qmail# qmailctl restart
Restarting qmail:
* Stopping qmail-smtpdssl.
* Stopping qmail-smtpd.
* Sending qmail-send SIGTERM and restarting.
* Restarting qmail-smtpd.
* Restarting qmail-smtpdssl.

This solved the issue and now mails are forwarded without problems via the Qmail SMTPD.

How to solve qmail /usr/local/bin/tcpserver: failed to map segment from shared object: Cannot allocate memory

Saturday, April 30th, 2011

Reading Time: 2minutes
If you’re building (compiling) a new qmail server on some Linux host and after properly installing the qmail binaries and daemontools, suddenly you notice in readproctitle service errors: or somewhere in in qmail logs for instance in/var/log/qmail/current the error:

/usr/local/bin/tcpserver: error while loading shared libraries: failed to map segment from shared object: Cannot allocate memory

then you have hit a bug caused by insufficient memory assigned for tcpserver in your /var/qmail/supervise/qmail-smtpd/run daemontools qmail-smtpd initialize script:

This kind of issue is quite common especially on hardware architectures that are 64 bit and on Linux installations that are amd65 (x86_64) e.g. run 64 bit version of Linux.

It relates to the 64 bit architecture different memory distribution and thus as I said to solve requires increase in memory softlimit specified in the run script an example good qmail-smtpd run script configuration which fixed the failed to map segment from shared object: Cannot allocate memory I use currently is as follows:

#!/bin/shQMAILDUID=`id -u vpopmail`NOFILESGID=`id -g vpopmail`MAXSMTPD=`cat /var/qmail/control/concurrencyincoming`# softlimit changed from 8000000exec /usr/local/bin/softlimit -m 32000000 /usr/local/bin/tcpserver -v -H -R -l 0 -x /home/vpopmail/etc/tcp.smtp.cdb -c "$MAXSMTPD"
-u "$QMAILDUID" -g "$NOFILESGID" 0 smtp
/home/vpopmail/bin/vchkpw /bin/true 2>&1

The default value which was for softlimit was:

exec /usr/local/bin/softlimit -m 8000000

A good softlimit raise up values which in most cases were solving the issue for me are:

exec /usr/local/bin/softlimit -m 3000000

or exec /usr/local/bin/softlimit -m 4000000

The above example run configuration fixed the issue on a amd64 debian 5.0 lenny install, the server hardware was:

CPU: Intel(R) Core(TM)2 Duo CPU @ 2.93GHz
System Memory: 4GB
HDD Disk space: 240GB

The softlimit configuration which I had to setup on another server with system parameters:

Intel(R) Core(TM) i7 CPU (8 CPUS) @ 2.80GHz
System Memory: 8GB
HDD Disk Space: 1.4Terabytes

is as follows:

QMAILDUID=`id -u vpopmail`
NOFILESGID=`id -g vpopmail`
MAXSMTPD=`cat /var/qmail/control/concurrencyincoming`
exec /usr/bin/softlimit -m 64000000
/usr/local/bin/tcpserver -v -H -R -l 0
-x /home/vpopmail/etc/tcp.smtp.cdb -c "$MAXSMTPD"
-u "$QMAILDUID" -g "$NOFILESGID" 0 smtp
/home/vpopmail/bin/vchkpw /bin/true 2>&1

If none of the two configurations pointed out in the post works, for you just try to manually set up the exec /usr/bin/softlimit -m to some high value.

To assure that the newly set value is not producing the same error you will have to, reload completely the daemontools proc monitor system.
To do so open /etc/inittab comment out the line:


Save again /etc/inittab and issue te cmd:

linux:~# init q

Now again open /etc/inittab and uncomment the commented line:

#SV:123456:respawn:/command/svscanboot to

Lastly reload the inittab script once again with command:

linux:~# init q

To check if the error has disappeared check the readproctitle process, like so:

linux:~# ps ax|grep -i readproctitle

The command output should produce something like:

3070 ? S 0:00 readproctitle service errors: .......................................

Hope that helps.