MikroTik CRS112 Basic switching setup

CRS112-8G-4S-IN CRS112-8P-4S-IN

The MikroTik CRS switches are absolutely awesome! You get a full featured, managed, wire speed switch combined with a SoC running RouterOS.But on the “downside” the configuration can be very complex and requires some deeper knowledge about switching and linux networking in general – as a linux user you will love it ;) Step 1 […]

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Gitea 1.5 on MariaDB 10.1

utf8mb4_general_ci; specified key was too long; max key length is 767 bytes

Error Messages#

In case you’ve tried to upgrade to Gitea 1.4 or 1.5 on Debian 9 with MariaDB 10.1 the following error messages will thrown to your log and the service won’t start:

[...itea/routers/init.go:60 GlobalInit()] [E] Failed to initialize ORM engine: migrate: 
do migrate: Sync2: Error 1071: Specified key was too long; max key length is 767 bytes


The issue is caused by the newly introduced charset utf8mb4_general_ci which is set to default in Gitea >=1.4. This charset requires 4 bytes per character and the indexes on utf8mb4_general_ci fields (varchar 255) won’t fit into the InnoDB scheme.


The only reliable solution is an upgrade to MariaDB 10.2 or 10.3. Just changing settings like innodb_large_prefix=1 or innodb_file_format=Barracuda as mentioned on several sites won’t have any effect to existing tables.


I’ve used a legacy version of Gitea (1.2.3) for a long time which was created initially as utf8_general_ci scheme. Therefore i’ve decided to alter the table + field charsets manually via phpmyadmin and set them to utf8_general_ci.

You have to run the upgrade procedure (start gitea executable) a several time because new tables are not created at once (repeat it 3..5 times).

Finally it works but i’m not sure if there will be any side effects in the future..

Ubuntu 15.10 with Dell Wireless 5570 HSPA+ (42Mbps) Mobile Broadband Card

mbmi to qmi modeswitch, magical ffc-auth sequence

A several days ago, i’ve replaced the Gobi 2000 WWAN Card with a newer version, a Dell 5570 Module. It’s a branded Sierra Wireless card, so i hoped it will work out of the box on Ubuntu 15.10 – but nothing. After some investigations if figured out, that the card is locked in “low-power” / […]

Install Sophos UTM Essential Firewall 9.3 with an USB Stick

plug ‘n play ? not really… (version 9.308-16.1)

First of all, you need to download the iso image (it’s required to create an account – your license key will be sent to this email address).

Install the ISO Image to an USB Drive#

It’s not possible to copy the image via dd directly to the usb drive because of a missing usb bootloader. Therefore you need external bootloader like Universal-USB-Installer from pendrivelinux.

Download and execute the tool.

  • Step 1 choose “Try unlisted Linux ISO” from the bottom of the page.
  • Step 2 select the iso image e.g. asg-9.308-16.1.iso
  • Step 3 select your usb drive (at least 2GB)

After the installation has finished, remove and reattach the usb stick from your system to process with the next step.

Fix the local package repository#

The current (9.308-16.1) iso image has some broken filenames within the local package repository. The files are located under “install/rpm/”. Check each file if it ends with “.rb1.i686.rpm” – if not, modify the filename and add the missing part!

Otherwise the installation will abort and message like “can’t stat file /install/install/rpm/….. rb1.i686.rpm” will appear. I hope this issue will be fixed soon…

Now you can attach the usb stick to your firewall-box and power it up!

Remount the USB Drive#

Ready ? not really… the hardware-detection of the installer will unmount the usb stick, which cause the error message “install.tar not found”. Therefore you have to remount the usb-stick after the hardware detection succeed.

  • After Hardware Detection succeed press “ok”
  • Select the Keyboard Layout and Timezone
  • Press “Alt+F2” to switch to the console
  • Re-Mount the USB drive: mount /dev/sdb /install
  • Press “Alt+F1” to return to the installer
  • Proceed the installation


Cryptex 4.0 with Retina/HighDPI support

behind the scene – high-resolution, css based images using media queries

The Story# No scrapers. No harvesters. No spambots. That’s our goal. A several years ago, i’ve released the first version of the Crypex Plugin to protect E-Mail-Addresses on WordPress based websites. It works great but currently many mobile devices like tablets, smartphones are using high-dpi displays which results in blurred E-Mail-Addresses. Therefore i’ve create a […]