udev (user space /dev) is a user space system that enables the operating system administrator to register user space handlers for events. The events received by udev's daemon are mainly generated by the Linux kernel in response to physical events relating to peripheral devices. As such, udev's main purpose is to act upon peripheral detection and hot-plugging, including actions that return control to the kernel, e.g. loading kernel modules or device firmware. Another component of this detection is adjusting the permissions of the device to be accessible to non-root users and groups.

As the successor of devfsd and hotplug, udev also manages device nodes in the /dev directory by adding, symlinking and renaming them. udev replaces the functionality of both hotplug and hwdetect.

udev handles separate events concurrently (in parallel), leading to a potential performance improvement over older systems.

We know that using swap space instead of RAM (memory) can severely slow down the performance of Linux. So then, one might ask, since I have more than enough memory available, wouldn’t it better to remove swap space completely? The short answer is, No. There are performance benefits when swap is enabled, even when you have more than enough ram.

Despite overall Elasticsearch stability, it is still possible for a cluster to get into a "red" state. One of the reasons for that to happen is if an index becomes corrupt. This can be caused by an abrupt loss of power, hardware failure or—more commonly—running out of disk space. In this post we'll discuss how to bring the cluster to a healthy state with minimal or no data loss in such situation.

Inconsolata is my first serious original font release. It is a monospace font, designed for code listings and the like, in print. There are a great many "programmer fonts," designed primarily for use on the screen, but in most cases do not have the attention to detail for high resolution rendering.