Following an upgrade from Lenny to Squeeze, there is a change in time format in the backup2l list files. This results in a full backup being made even though a lot of the data haven’t changed.

The solution is to do a new top-level backup immediately, i.e. provide a new baseline. However you might find that this removes an entire set of previous backups. This is the recommended procedure in the manual page "shortly before or after major changes are performed with the file system. In this case, a lower level should be specified in order to avoid that a large number of files are backed up multiple times again."

To do this, run

sudo backup2l -b 0

People are reporting various phpMyAdmin / SquirrelMail failures. e.g.

The current solution to this is tweaking the PHP5 Suhosin configuration file, or removing PHP Suhosin completely. Suhosin plays a role in keeping your machine secure against badly coded applications. There is more information about it, and why it should be used on its website.

The Suhosin configuration is kept in /etc/php5/apache2/conf.d/suhosin.ini. The item to change is suhosin.session.encrypt and it should be uncommented and set to off. Once done, Apache should be restarted.

sudo /etc/init.d/apache2 restart

The alternative is to remove Suhosin. Please consider the security implications before doing this. To remove it run the following command.

sudo apt-get remove --purge php5-suhosin

There are a couple of emails that might get set regularly by cron. The first references PHP5 mhash.ini which is a deprecated module. To fix run

sudo apt-get remove --purge php5-mhash

The second is one complaining that /usr/sbin/exim_rewrite_scan cannot be found. To fix that remove /etc/cron.d/exim_rewrite_scan.

There were a couple of race condition causing the firewall to trigger itself to run again whilst running.

This is now fixed in the latest packages and your machine should automatically update itself.

Plain text logins have been disabled in the IMAP and POP3 server unless the connection is encrypted. This is to prevent transmission of unencrypted passwords. A typical error shown by an email client might be as follows.

There are two solutions.

As far as possible Symbiosis will discourage you from using root when logging in and configuring the system. This primarily applies to

For example, if a directory in /srv is owned by a system user or group, i.e. one with a UID/GID less than 1000, then it will not show up to various tasks, including, but not limited to,

In short, try not to use root if at all possible.

However it is perfectly possible to configure separate domains in /srv/ to be owned by different users, as long as they are non-system users, i.e. ones with user IDs greater than 1000. All programs will respect these permissions.

Lots of configuration on the system is automatically generated to make Symbiosis work as it does. In previous releases of Symbiosis this meant that files would get overwritten without notice. However as of the Squeeze release in February 2012 configuration files are handled more conservatively.

Two things to watch out for. If a configuration file has

# DO NOT EDIT THIS FILE - CHANGES WILL BE OVERWRITTEN

written in it, then there is a high chance that any changes will be overwritten. It has to be the exact wording and spacing above for overwriting to take place, so if that sentence is removed from the configuration then it will not get overwritten.

Similarly many files are generated from templates, for example DNS and apache snippets. These will now have a checksum at the bottom of the file.

# Checksum MD5 586732ff59e60115d0ec1c4905c72773

This checksum allows Symbiosis scripts to establish if the template used to generate the snippet has changed, if the data used in the generation has changed, or if the file itself has been edited. For example if an IP address is changed by editing config/ip, then that would allow the apache snippet for that domain can be updated, as can the DNS snippet.

This also means that sysadmins can edit the templates, and allow them to regenerate, or edit the snippets themselves safe in the knowledge that their changes will not get overwritten.

The Backup2l, Dovecot, and Exim configuration files are generated not with a template, but with a collection of snippets, which are joined and checked using a Makefile. This allows extra configuration snippets to be added in to the configuration.

If it is deemed necessary, sysadmins can add extra snippets to these configurations. The basic procedure is to read the configuration file, and decide where the extra directives need to go. This is made easier by the fact that through the configuration files comments are added showing where each part comes from.

# ------------------------------------------------------------------------------
# /etc/exim4/symbiosis.d/10-acl/40-acl-check-mail/00-header
# ------------------------------------------------------------------------------

# ACL that is used after the MAIL command
acl_check_mail:

# ------------------------------------------------------------------------------
# /etc/exim4/symbiosis.d/10-acl/40-acl-check-mail/90-default
# ------------------------------------------------------------------------------

# Allow anything not already denied to connect
  accept

In this example, if an extra directive were required in this ACL, then a file could be created in /etc/exim4/symbiosis.d/10-acl/40-acl-check-mail/, maybe with the filename 10-do-stuff. To create the new configuration, we’d then need to run make in /etc/exim4/. This would regenerate /etc/exim4/exim4.conf, and perform a basic syntax check. If happy with the new configuration, then exim4 could be restarted.

The equivalent Dovecot configuration is in /etc/dovecot/symbiosis.d/ which generates /etc/dovecot/dovecot.conf. The Backup2l configuration is in /etc/symbiosis/backup.d/conf.d/, which generates /etc/symbiosis/backup.d/backup2l.conf.