Guido Flohr - #System Administration

Formatting Large Hard-Disks On Mac OS X

Sun, 26 Nov 2017 22:00:00 +0000

My new LaCie rugged USB-C drive showed only a capacity of 372 MB instead of the 4 TB that I had bought, when I formatted the disk on Mac OS X High Sierra. It turned out that I first had to create a GUID Partition Table (GPT) on it to use the full capacity.

Simple Dynamic DNS

Mon, 15 Feb 2016 22:00:00 +0000

Most routers for home internet allow you to forward ports of your publicly visible IP address to internal IPs of your home network. In order to make that work, you first need to know your publicly visible IP. Most of the time, the router will fetch its IP from the ISP via DHCP, and the address is not constant. This is where countless dynamic IP services jump in, with the disadvantage that the names that they offer are mostly plain ugly (my-name.dynamic-ip-xyz.example.com) and most of the time they will make you pay for everything but the most basic services. If, however, you are the admin of the nameserver of your domain you can easily set up your own solution.

The Gory Details of URL Validation

Fri, 10 Jan 2020 22:00:00 +0000

I currently work on a web application that allows users to supply a link to their homepage. Such links have to be validated client-side with JavaScript (actually Typescript/Angular) and with Perl on the server-side. But what should be accepted as a valid homepage link? And what is the right approach to analyze the provided URLs?

Multilingual Web Sites with Jekyll

Fri, 26 Feb 2016 22:00:00 +0000

After waiting years on my TODO list I recently decided to tackle the project "web site". Since I no longer work for Imperia I was looking for a light-weight alternative. I did not want to install PHP on my server, ruling out a lot of options. A colleague finally recommended Jekyll. Its simple semi-static approach reminded me of Imperia and I decided to give it a shot.

Tar Option 'v' Considered Harmful

Sun, 27 Dec 2015 22:00:00 +0000

The utility tar should rather be renamed to vtar. Why the heck does almost everybody add the option v automatically? Is that in any way helpful? Or is it maybe even dangerous?

Simple Content Negotiation For Nginx

Sun, 28 Feb 2016 22:00:00 +0000

Content negotiation is a key concept for multi language web sites. For Nginx it is only available as a patch. But negotiating the language is a rather trivial task for most sites. Instead of patching the web server, a couple of lines of Perl code will also do the job.

Group Authentication For Nginx

Tue, 13 Sep 2016 21:00:00 +0000

The access control system of Nginx lacks an equivalent for Apache's group based access control. But it is easy to emulate this Apache feature with a little bit of scripting.