You can check if you have xcache installed by doing sudo dpkg -s php5-xcache | grep Status. If the status shows as "deinstalled" but with config files left, you can simply purge it with sudo apt-get remove --purge php5-xcache .

Then restart Apache: sudo service apache2 restart. Your error log should now be spam free.

So I wasn’t pleased to find my postfix-dovecot installation dying on upgrade from 11.04 to 11.10. I couldn’t sent outgoing mail or receive inbound.

Fortunately I wasn’t an “early upgrader”… both issues were easy to find and fix.

Fixing inbound mail

Messages sent to my address were being returned as undeliverable with the following error:

            < my-server.com #5.3.0 x-unix; /usr/lib/dovecot/deliver: invalid option -- 'n' Usage:    dovecot-lda [-c ] [-a 
] [-d ] [-p ]    [-f ] [-m ] [-e] [-k]>

This is fairly self-explanatory: In the new version of Dovecot, the “n” option is no longer used. If you receive this error, type the following commands:

sudo postconf -e "mailbox_command = /usr/lib/dovecot/deliver -c /etc/dovecot/conf.d/01-mail-stack-delivery.conf -m \"\${EXTENSION}\""
sudo service postfix restart 

Done.

Fixing outbound mail

My errors were caused by the SASL authentication server, saslauthd. A bug report is here.

The problem can be fixed by rolling back saslauthd packages to a previous version, then “sticking” them so that they don’t get updated with regular system updates. Keep track of this so that you can remember to un-stick them when it comes time to upgrade.

First get the old packages. Replace “i386″ in the links below with “amd64″ if your server is 64-bit

mkdir ~/saslfixes
cd ~/saslfixes
wget http://archive.ubuntu.com/ubuntu/pool/main/c/cyrus-sasl2/libsasl2-2_2.1.23.dfsg1-5ubuntu3_i386.deb http://archive.ubuntu.com/ubuntu/pool/main/c/cyrus-sasl2/libsasl2-modules_2.1.23.dfsg1-5ubuntu3_i386.deb http://archive.ubuntu.com/ubuntu/pool/main/c/cyrus-sasl2/libsasl2-dev_2.1.23.dfsg1-5ubuntu3_i386.deb http://archive.ubuntu.com/ubuntu/pool/main/c/cyrus-sasl2/libsasl2-modules-sql_2.1.23.dfsg1-5ubuntu3_i386.deb http://archive.ubuntu.com/ubuntu/pool/main/c/cyrus-sasl2/sasl2-bin_2.1.23.dfsg1-5ubuntu3_i386.deb

Then remove the old packages and install the new ones:

sudo /etc/init.d/saslauthd stop
sudo dpkg -r libsasl2-dev
sudo dpkg -r libsasl2-modules-sql
sudo dpkg -r sasl2-bin
sudo dpkg -r --force-all libsasl2-2 libsasl2-2:i386
sudo dpkg -r --force-all libsasl2-modules
sudo dpkg -i --force-all *.deb

Then restart the servers:

sudo /etc/init.d/saslauthd restart
sudo /etc/init.d/postfix restart

And finally “stick” the packages so they aren’t updated:

Type these commands as root (sudo su - will get you a root shell)

echo libsasl2-dev hold | dpkg --set-selections
echo libsasl2-modules-sql hold | dpkg --set-selections
echo libsasl2-2 hold | dpkg --set-selections
echo libsasl2-modules hold | dpkg --set-selections
echo sasl2-bin hold | dpkg --set-selections