GNU Linux

Release hold queue email in Postfix – postsuper

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Postfix logo

How to flush Postfix’ mail queue from the command line and delete all mail from the queue? Easy, use the Postfix postsuper command as explained in this post. The postsuper command controls different types of queues in the Postfix mail system, like the deferred or hold queue. This post shows you some Postfix queue operations […]

GNU Linux

Recursive scp and symlinks

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Recursive scp without following symbolic links. TL;DR: when using recursive scp, symbolic links aren’t preserved and are copied as if they are normal directories. So you have to look for another solution to recursively transfer symlinks over ssh. Here is one: Tar over ssh!

Windows Server

Tunnel RDP through SSH & PuTTY

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How to tunnel Remote Desktop over SSH with PuTTY? Have you ever been in a situation where you needed to perform remote administration on a Windows Server, and the RDP port 3389 is blocked on a firewall? You can tunnel RDP over SSH with PuTTY. This particularly comes in handy when there is no VPN […]

GNU Linux

Turn off swap

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How to turn off swap in Linux. Not every Linux server I administer needs to have a swap partition and to start swapping. For instance, the MySQL servers I maintain all have more than enough RAM on board to do their work. Yet, when a swap partition is enabled Linux starts swapping, which may degrade […]

GNU Linux

Monit monitoring on Ubuntu 14.04 VM on Hyper-V

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Monit monitoring for websites and services, on an Ubuntu 14.04 LTS VM, hosted on a Windows Server 2012 R2 or Windows 8.1 Hyper-V. This post is about setting up a Monit monitoring service. Monit is a free and open source service monitoring application which can perform various event-based actions. Monit can send email notifications, restart […]

Security

Old-school: Unix wildcards gone wild

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DefenseCode’s Leon Juranic released an article explaining an old-school hacking technique: Unix wildcard poisoning attacks. No ASLR bypass, ROP exploits or 0day remote kernel exploits, but if you wonder how basic Unix tools like ‘tar’, ‘chmod’ or ‘chown’ can lead to full system compromise, keep on reading.