Category Archives: Short Tips

Short Tip: Replacing a failed drive in mdadm softwareraid

Posted on 13. May 2016 by bastelfreak

Sometimes you check your fileserver and your raid looks like this: # cat /proc/mdstat Personalities : [raid1] [raid6] [raid5] [raid4] md125 : active (auto-read-only) raid6 sdl[1] sdh[7] sdf[5] sdk[2] sdg[6] sdm[8] sdi[0] sdn[10] sde[4] 23441080320 blocks super 1.2 level 6, … Continue reading →

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Linux Short Tip: Correct IPv6 with ferm firewalling

Posted on 11. May 2016 by bastelfreak

I mentioned ferm in my last post about gluster (an iptables/ip6tables abstraction layer in perl with a nice firewall config). The default rule-set looks like this: Most people attend to C&P that blog and wrap it in domain ip6 {} … Continue reading →

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Short Tip: Setup glusterfs share on Arch Linux

Posted on 11. May 2016 by bastelfreak

I made a detailed tutorial for a Arch Linux installation a few days back. This is a quick follow up post to create a Distributed-Replicated gluster share. The goal is to create a mirror for several linux distributions. A mirror … Continue reading →

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Short Tip: Fiddling around with login shells

Posted on 3. May 2016 by bastelfreak

I’m currently playing around with LARS, this script collection creates a arch ISO with some post-install magic, for example setting a login shell for root. The used code is: I could boot up the image and ssh into it with … Continue reading →

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Short Tip: git magic (copy changed files from branch A to B)

Posted on 24. January 2016 by bastelfreak

Let us consider the following case: I’ve got a huge project which you want to refactor. You checkout master, create a branch called cleanup and commit every change. Most of the refactoring is only style guide related so no change … Continue reading →

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Short Tip: tuning Zabbix Database Part 2

Posted on 14. January 2016 by bastelfreak

[part 1] Besides disabling autovacuum you can also try to increase the performance if you have got enough free resources. There are three important options for this: autovacuum_vacuum_cost_delay I lowered the sleep between two autovacuums to 0.2ms autovacuum_vacuum_cost_limit/vacuum_cost_limit (setting autovacuum_vacuum_cost_limit … Continue reading →

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Short Tip: tuning Zabbix Database

Posted on 12. January 2016 by bastelfreak

I am currently running a zabbix setup which is a bit bigger than the average ones, right now it receives ~2100 new values per second, generated by 169052 items. The data is stored in a postgresql database, and I am … Continue reading →

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Short Tip: Moving commits between branches

Posted on 11. January 2016 by bastelfreak

Sometimes you are developing on a huge new feature on a software project. If you are smart you do it in a separate (feature-) branch. During the development cycle you may modify existing code and after a few days you … Continue reading →

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Securing Postfix on a shared Webserver

Posted on 3. December 2015 by bastelfreak

I’m operating a webserver for shared webspace accounts. I’m not responsible for the stuff hosted on the webspace, but for the server itself. Many people like to host their wordpress or joomla on this server, both scripts are well known … Continue reading →

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Fighting PHP spam

Posted on 1. December 2015 by bastelfreak

A good friend owns a very old joomla website which has been hacked. It is massively sending spam, how can we investigate this? First of all, reject outgoing mails in your firewall (ferm.conf style): Now we have time to investigate. … Continue reading →

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