2016 seems to be the year of hardware upgrades for me. After replacing my ESXi host with a VSAN cluster recently, I also had to replace the D.I.Y. router after upgrading my internet connection. At maximum data throughput, CPU load and temperatur are increasing so heavily that other network traffic is slowing down …

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As preparation for a restore test, I removed the master boot record (MBR) of a Linux system recently: 1# dd if=/dev/zero of=/dev/sda bs=512 count=1 This command fills the first 512 bytes (containing the partition table and bootloader) of the first hard drive (/dev/sda) with zeroes (/dev/zero). The problem is when you …

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Sometimes it happens that you lock out yourself from your Linux system. In the worst case, additional security concepts or conditions might hamper access to the system, for example: No root access System cannot be rebooted to reset the password in a chroot session No colleague with system access available Recently I …

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Thanks to the lcd4linux project, Linux also offers the possibility to control LC display - e.g. to display status information. Some years ago, a very cheap digital picture frame was sold on mail-order houses like Pearl. Using an alternative firmware, this device is also capable of being controlled by lcd4linux. Since …

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Since 2008 I have been using the free Linux distribution IPCop to implement a customized firewall/a router. Of course, DSL providers also equip their customers with routers, but back then I was missing a couple of functions. To name some of them: IPSec / OpenVPN NTP time server DMZ segmentation WLAN access point with …

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With the new major version 8, GitLab was extended to include a continuous integration (CI) component that was developed as dedicated project until now. While it was necessary to utilize external solutions, such as Jenkins, previously, it it now possible to automatically compile and test managed projects easily. But, …

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While registering a client system with a FreeIPA server I recently stumbled upon the following error message: 1# ipa-client-install 2... 3User authorized to enroll computers: admin 4... 5Kerberos authentication failed 6kinit: Cannot read password while getting initial credentials After wasting quite a lot of time with …

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IOmeter is a collection of tools for running detailed IO benchmarks. It is often used as the tool is able to reproduce the characteristics of current applications and services. IOmeter consists of a management software that manages and evaluates the particular tests and Dynamo - an executable that run these tests in …

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Koukaam NETIO power outlets offer a network interface that can be used for controlling the particular ports comfortably. It would be even nicer to monitor them with Nagios or Icinga. 2012 I created a provisional bash script for monitoring the ports and time synchronization over NTP. This weekend I migrated the script …

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While testing a web application that uses PHP PDO to establish a connection to a PostgreSQL database I stumbled upon the following error message: 1Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[08006] [7] FATAL: Ident authentication failed for user "user"' in xxx.php Surprisingly I was able to …

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