How to ping BackupPC hosts behind a NAT router or firewall

BackupPC is a very capable open-source enterprise-grade backup system that is readily available for most Linux distributions, e.g., Ubuntu, Debian and Fedora. However, since most computers today are behind a NAT router or firewall, this completely breaks the ping command that a remote BackupPC server uses to check if a host client is alive or reachable. The most common solutions which allow BackupPC to ping host clients that are behind a NAT router or firewall are discussed here.

BackupPC, being open source and free, is great in many aspects and thus has also become the backup system of choice in many enterprise environments as well as home networks. Although it usually works out-of-the box in most popular Linux distributions, such as Ubuntu, Debian and Fedora, some quirks do exist. For example, the broken GUI interface caused by Apache. Another example, which is discussed here, is the ping system that BackupPC uses to check if a host computer client is alive. In addition, it will be argued why some common solutions provided on the internet are better than others based on experience and logic.

The scenario that is particularly considered is the case of a remote BackupPC server attempting to backup multiple computers that sit behind a NAT router with firewall, as illustrated in the picture above.

Flashcache 3.0 released by Facebook to enhance SSD

Flashcache is a highly open-source (GPL2) regarded software developed by Facebook which aim to reduce the wear of SSD disks while simultaneously enhance the performance. Now, Facebook has released Flashcache 3.0 to the public.

Facebook clearly deals with massive amounts of data in every given instance. During the past few years, Facebook has gradually migrated to SSDs in favor of the conventional mechanical disks. The enhanced read/write performance of SSDs, in particular when it comes to seek times during random events, results in significantly faster user-content serving, something which obviously enhances the user experiences. However, while SSDs offer excellent performance, the inherent nature of the underlying flash memory technology means that each module can only be written to a finite number of times before it malfunctions.

Linux cuts costs by 40% for French police

The French police have recently migrated from Windows to Linux, affecting 37000 computers at present and with another 72000 computers coming up. This migration resulted in a cost reduction of 40%.

Whether or not open source platforms can reduce costs or not is often up for debate, and in particular the migration from Windows to Linux is a very delicate topic. While some claim that it is obvious that a switch to an open-source platform would reduce the costs significantly due to the free license forms, others claim that a migration to open source platform always is associated with lots of hidden costs, such as training, re-implementation of processes and reduced support, which in the end could be more expensive than supported proprietary options. There are examples that support both camps but the latest example by the French police department is in favor of the open-source camp.