Category Archives: Linux

Linux System Administration

Another Bash One Liner To Delete Old Directories View Comments

We received a tip from blog readers Christian and Michael for alternatives to the command to delete all directories older than a certain period of time. These both work in bash and can be used in scripts to clean up old backup directories or any situation where you need to delete old directories from the [...]

One Line Batch Rename Files Using CSV Input File and awk View Comments

The Bash command environment, which is the namesake of this blog, is very flexible in that it allows you to manipulate the filesystem in many ways. Awk and sed are very powerful tools that allow you to do this rename with a simple one line command. This post will walk you through doing this with [...]

Linux Command Line, Generating a Random File View Comments

It is very easy to create a random file using the linux command line. Much like the command to fill a file with all zeros, for example a 1 Meg file: dd if=/dev/zero of=zero.filename bs=1024 count=1000 You do the same using /dev/urandom: dd if=/dev/urandom of=random.filename bs=1024 count=1000 Resulting in a 1MB file: 1000+0 records in [...]

Tweaking TCP for Fast (100mbps+) Connections and Transfers on Linux View Comments

We recently did some speed testing on a few of the servers on our network, and we were not receiving the speeds expected considering they were sitting on a physical 100mbps ethernet port. The servers were indeed on physical 100mbps connection, however wget (TCP/IP, HTTP Port 80) download tests showed only a max of about 1.5MB/sec (note the 8bit/byte conversion, so this translates to about 12mbits).

How to Install SNMP on Tomato Router Firmware and Graph Traffic with Cacti View Comments

You’ve flashed your old WRT54G or other vanilla router with the Tomato firmware. This itself turns your router into a lean, mean routing machine with QOS, SSH and more, but let’s say we want to take it a bit further. What it we want to get some more stats out of it? In order to [...]