ACLs: Linux advanced privileges

Another part of the RHCSA exam is some advanced privileges, mainly reading and setting Access Control Lists (ACLs). Again not too complicated, but its good to have some pointers. Probably more familiar to you are standard POSIX permissions: permissions for the owner of a file, a group and all others. But what when you need…

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Setup a NFS client on Red Hat / CentOS

So this first thing that needs a bit of work on my end, starting on my RHCSA adventure, is to setup a NFS client. It’s not too hard but there are a couple of things to consider and things like firewall and SELinux that can be easily overlooked. The RHCSA exam focuses on the NFS…

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Fast Postfix and Dovecot setup on Ubuntu 18.04

More than a year ago I did a comprehensive multiseries walkthrough about how to setup a mailserver using Postfix and Dovecot, with antispam, database backend, etc. I’ve been running it ever since without a hiccup. For my recent LFCS certification I had to brush up on this knowledge a bit and wanted to find out…

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Linux swap file and encrypted volumes

As with the last post, this seems like two pretty different subjects, a swap file and encrypted volumes, but for me it makes sense, because it’s all in preparation for the LFCS exam as mentioned here and here. First I want to make a small addendum on the creation of swap space; this time a…

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Setup Linux swap and quotas

Swap and quotas. Two seemingly random subjects in one post, but for me it really has a purpose: preparation for the LFCS exam as mentioned here and here. The exam might also contain questions on encrypted storage, linux RAID and automounting of samba shares, but to me this seems so random and not at all…

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Create and expand volumes using LVM

My coming LFCS exam as mentioned in my last post, consists of about 15% of storage specific questions. LVM has a large part in it. Since I rarely need storage tools (it’s so much easier in a virtual environment), I decided to write something about it, to hopefully make it stick in my mind. Pretty…

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Grafana dashboarding using Graphite

Something completely different in contrast to the last few weeks: Grafana dashboarding, using Graphite metrics. A great while ago I’ve introduced and setup Icinga 2 and Icinga Web 2 to monitor our relatively new managed hosting platform. I’ve written a couple of posts about it, starting here. Not too long after that I’ve added Graphite…

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More Debian vs Ubuntu stuff

Last week I’ve explained a bit why I’m considering jumping from Debian to Ubuntu to get our managed hosting a bit more up-to-date by default, instead of using 10 third party repos. This week I would like to specify more about our managed hosting tooling, what we’re using for Debian, what we might like to…

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From Debian to Ubuntu?

Ubuntu. Oh my. This is awkward. When I started out experimenting with Linux, I opted for CentOS since it is one of the most stable versions out there. You’ll soon find out though, that the software in the repos is too old for many situations in the web application industry. Right before I started working…

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Monitor cron with Icinga

I’m a big Icinga fan and have written about it a couple of times. Check out this awesome series for Debian. Now people have asked a better way to monitor cron (jobs). Can we integrate this into Icinga? I’ve looked at a couple or solutions that are out there, but the most obvious is to…

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Install Zammad on Debian 9

Last post was a nice intro on how I’ve found Zammad, an open source, nice looking support ticket system. Will it handle all the requirements I’ve set in last post and be ‘the one’? Let me immediately spoil that for you: it’s almost perfect and Zammad will be my choice for sure. Installing it is…

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Linux open source ticket system

For a new project, I’m looking for a Linux open source ticket system. It’s main purpose is for support tickets, but it would be awesome if it could handle ‘normal’ customer conversation as well in an efficient and nice way. I remember I’ve looked for this a couple of times already in the past and…

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Using Linux GNU screen

OMG choices, choices. Almost a year ago my colleague introduced me to screen: a cli/terminal window manager that multiplexes a physical terminal between several processes, typically interactive shells. Simply put: multiple shells in one shell. But there is at least one application that is said that does it better: tmux. So we’ll be using that…

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Essential and practical vi – Part 3

What started out as a plan to make a not too complex post about vi buffers, turned out to be a 3 part post with lots of essential bits and pieces on this awesome editor. So also see part 1 and part 2. There is even more advanced things I could write about like the…

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Essential and practical vi – Part 2

First, check out this nice post about every day, very practical vi stuff you can’t do without. Originally I only wanted to do a piece on vi buffers but the post grew and grew and here we are, at the second part. In this post I want to explain some searching, search and replacing, more…

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