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Posts in Linux
A quick and easy way to rotate and resize images in Ubuntu Linux
I've been using the ImageMagick package for several years to resize and rotate images that I link to on my blog. Both operations are super easy to do with the convert utilities "-resize" and "-rotate" options. The following command will shrink an image by 50%: To rotate an image 90 degrees you can use "-rotate": Man convert(1) provides a TON more detail along with descriptions of numerous other conversion options.
$ read more →Installing NVidia binary drivers on an Ubuntu 16.10 desktop
I recently upgraded my Ubuntu 16.10 desktop with an NVidia GeForce 730 graphics adapter. My experiences with the nouveau opensource driver haven't been good so I decided to install the binary drivers from NVidia. Ubuntu makes this process INCREDIBLY easy. To install the latest NVidia drivers you can click the "Search your Computer" icon in the Unity menu, type in "Drivers" and then click additional drivers…
$ read more →Getting more out of your Linux servers with moreutils
I accidentally came across the moreutils package a few years back and the day I did my life changed forever. This package contains some killer utilities and fill some nice gaps in the *NIX tool chain. Here is a list of the binaries in this package (descriptions taken from the man page of each utility): I'm especially fond of errno, chronic and pee. But my favorite utilities have to be ifne and ts…
$ read more →Viewing Linux tape drive statistics with tapestat
A while back I wrote a blog entry showing how to get tape drives statistics with systemtap. This script wasn't very reliable and I would frequently see it crash after collecting just a few samples. Due to the work of some amazing Linux kernel engineers I no longer have to touch systemtap. Recent Linux kernels now expose a number of incredibly useful statistics through the /sys file system: There is also a tapestats utility in the syststat package that can be used to summarize these statistics: This is a useful addition and I no longer have to worry about systemtap croaking when I'm tracking down issues.
$ read more →Using systemd to restart processes that crash
The gmetad process on my Ganglia server has been a bit finicky lately. Periodically it segfaults which prevents new metrics from making their way into the RRD databases it manages: Luckily The gmetad service runs under systemd which provides a Restart directive to revive failed processes. You can take advantage of this nifty feature by adding "Restart=always" to yourunit files: Now each time gmetad pukes systemd will automatically restart it. Hopefully I will get some time in the next few weeks to go through the core file to see why it keeps puking…
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