Author: jean

Setup a central logging instance (and use it to block traffic using fail2ban)

A very light-weight approach for storing logs centralized is by just using rsyslog. My virtual machines all use rsyslog. That rsyslog sends it’s logs to another internal virtual machine which runs rsyslog as well. A fail2ban instance is checking all these logs and sending a block command to the firewalls. Here is how.

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Encrypting existing volumes in ZFS using zfs send and zfs recv

Let’s say you want to encrypt your previously not encrypted data – in my example a ZFS pool. A good way to do so is to simply use zfs send and zfs receive. These commands can be used to transfer ZFS data streams. The procedure is pretty simple. Create a snapshot, transfer this snapshot using zfs send and receive it using zfs receive.

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Encryption of ZFS volumes using a remote / external key-system written in PHP

I thought a long time about what security benefits I have if I store the encryption key of a volume on the same system (locally). Let me share some of these thoughts with you. Then I’ll show you my approach using a self-written key-system in PHP (using RedBeanPHP and Sqlite) and finally I’ll show you how to use this with ZFS.

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Amavis’ cool features

I guess that most people use amavisd-new together with spamassassin and for example ClamAV. Probably a few more use features like DKIM verification and signing with amavis. However, there are some features which aren’t found in the usual howtos. Here are some of them.

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systemd multi-instance Redis

Instead of working with one redis server instance I would like to use multiple instances of redis because that way I can limit memory and do additional tuning for the instances. systemd can help on this. I will create an instance for amavisd-new in this guide.

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