How to set up Linux chroot jails | Enable Sysadmin

Interested in using containers to isolate processes? Then explore the world of chroot jails: the original containers.

Source: How to set up Linux chroot jails | Enable Sysadmin

Android Central: How to get iMessage on Android

Android Central: How to get iMessage on Android.

Warning: it ain’t going to be easy and you’ll need a Mac running 24/7 and some config skills with you router. Is it worth it? Is Signal a better option anyway?

How to Install and Use Netdata Performance Monitoring Tool on Debian 9

How to Install and Use Netdata Performance Monitoring Tool on Debian 9

Using rsync to back up your Linux system ::

One of the most important features of rsync is the method it uses to synchronize preexisting files that have changed in the source directory. Rather than copying the entire file from the source, it uses checksums to compare blocks of the source and target files. If all of the blocks in the two files are the same, no data is transferred. If the data differs, only the block that has changed on the source is transferred to the target. This saves an immense amount of time and network bandwidth for remote sync.

Source: Using rsync to back up your Linux system ::

Rsync is pretty handy. You can even get it to work on Windows if you want.

Moving files around on a device with BusyBox

This is a super quick post on a simple method to exfiltrate data from systems running BusyBox, a shell commonly used on embedded devices. Such systems often lack common tools, presenting a challenge when you need to move data about.

Source: Exfiltrating files with BusyBox – Bitquark

This can really come in handy when working with phones or embedded devices. BusyBox is pretty widely used, but you’ll need a net connection obviously.

The rise of containers sparks #GIFEE and changes the world

This may sound a bit like an older technology called virtualization, but tools like DC/OS and Kubernetes takes things much further. For one, they can run massive quantities of software far more efficiently than virtualization ever could. “The magic of the container world is that the computational overhead is far less than full virtualization,” says Mike Stoppelman, the senior vice president of engineering at Yelp, which now runs its operation at DC/OS. “Even today, moving around a 20 megabyte container is so much easier than moving a 100 megabyte virtual image … and the network traffic created by this stuff is an order of magnitude less.”

— You Want to Build an Empire Like Google’s? This Is Your OS | WIRED

Good article that covers the basics of the new containerized world and serves as an introduction to the concept of “Google infrastructure for everyone else” #GIFEE. I think this is the future.

Command-line tools for collecting system statistics |

Command-line tools for collecting system statistics |

Netflix shows how they get a high level look at Linux in 60 seconds

In 60 seconds you can get a high level idea of system resource usage and running processes by running the following ten commands. Look for errors and saturation metrics, as they are both easy to interpret, and then resource utilization. Saturation is where a resource has more load than it can handle, and can be exposed either as the length of a request queue, or time spent waiting.

dmesg | tail
vmstat 1
mpstat -P ALL 1
pidstat 1
iostat -xz 1
free -m
sar -n DEV 1
sar -n TCP,ETCP 1

Some of these


  require the sysstat package installed. The metrics these commands expose will help you complete some of the USE Method: a methodology for locating performance bottlenecks. This involves checking utilization, saturation, and error metrics for all resources (CPUs, memory, disks, e.t.c.). Also pay attention to when you have checked and exonerated a resource, as by process of elimination this narrows the targets to study, and directs any follow on investigation. 

The Netflix Tech Blog: Linux Performance Analysis in 60,000 Milliseconds

Lots of good info here, though I suspect many sys admins already run through most of this once they land on a box.