Ubuntu

While trying to debug a postfix authentication issue in Debian 6, I had to use testsaslauthd to test things out:
testsaslauthd -s smtp -u foo@example.com -p test

only to get the following error:
connect() : No such file or directory 0

This is apparently because a lot of people (and authors) follow the same guide for configuring postfix and saslauthd. One of the steps missing is to symlink and saslauthd directory to a location within postfix. To fix:

While setting up Drupal on a friend's Ubuntu server, I ran into the following error message:

PHP Fatal error: Undefined class constant 'MYSQL_ATTR_USE_BUFFERED_QUERY' in /var/www/mysite/includes/database/mysql/database.inc on line 42

This basically simply means that the PHP PDO extension has not been installed. It can be installed via something along the lines of:
sudo aptitude install php5-mysql

While you are at it, make sure that all the other PHP extensions that Drupal requires are also installed.

Good luck :)

I just finished setting up postfix on a Debian 6 machine. All is peachy. However, when I checked my mail logs to see how things were going I noticed a number of entries for messages being sent from smmsp@example.com to root. Checking root's mail led to messages with the following content:
/usr/share/sendmail/sendmail: line 880: /usr/sbin/sendmail-msp: No such file or directory

I repeatedly ran into the following warnings while trying to update my Debian box using apt-get.

If you've ever worked with Debian or Ubuntu servers, you've very likely had to set up a firewall at some point or the other. However, any changes that are made are not saved and loaded if the server is ever rebooted. The following is a quick guide on how to get this happening:

(root or sudo access is required)

If you've ever visited a webserver's error page, it will usually state the error followed by information about the server. This will customarily tend to include the webserver software, its version, possibly information about some of the modules compiled in as well as the server's address and port. While this might look generous and helpful, it also allows bad guys as well as other parties to probe the server to find out what it is running as well as other details such as version information. This information can be used for nefarious purposes.

My upgrade from Lucid to Precise did not go well and I've been battling errors ever since. I ran into the following error when trying to reinstall the php5-gd extension for PHP:
No apport report written because MaxReports is reached already

After my upgrade from Lucid to Precise (and thereby, from MySQL 5.1 to 5.5), I found that my MySQL instance was not running. When I tried to start the service all I got back was that it had failed to start.

I checked the system log (sudo tail /var/log/syslog) to see if I could divine the cause of this issue and I found the following messages:
init: mysql post-start process (5075) terminated with status 1
mysql respawning too fast, stopped

After an upgrade from Lucid to Precise, my PHP install started complaining about a library:

PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib/php5/20090626+lfs/gd.so'

While I've got a hunch that the actual problem is related to issues I had during the upgrade, turning this error (and other similar ones) off is as simple as going into /etc/php5/conf.d and renaming the file, in this case gd.ini to something like gd.ini.bak.

So I tried updating one of my boxen running the Lucid Kubuntu LTS to the new Precise Pangolin beta. During the upgrade, I received an error message stating that adobe-flashplugin could not be upgraded. I ignored it and continued with the upgrade and all went swimmingly. Once the upgrade was completed and I had rebooted, when I tried to run an apt-get update, I ran into an error with respect to the adobe-flashplugin package. When I tried to remove it, it did not work. As a stop-gap measure, I removed a number of packages that depended on it including Firefox and sun-java6.