After putting my home server online running my blog and other applications accessible from the Internet, I left it unattended for a few days and then I found that I couldn’t access my blog from the Internet any more. It has been attacked by hackers using Denial-of-service attacks. Hackers created a large number of half-open TCP connections to the server and established connections to the Apache Web Server. The latter caused the Apache Web Server’s Prefork Multi-Processing Module (MPM) to spawn the maximum number of Processes allowed. This combination brought the server performance to a stand-still. The DMZ I created appears to be holding up as I did not find any evidence on hackers breaking through my second firewall. Continue reading Defending Hacking Attacks on My Home Server
For those who are not familiar with Odroid XU4 and CloudShell, Odroid XU4 is an ARM-based Octa core single board computer based on the Samsung Exynos5422 2Ghz Cortex A15 and Cortex A7 cores with 2 Gbytes of memory. CloudShell is a compact case for Odroid XU4 with a 2.2 inch TFT LCD and a USB 3 to SATA bridge for connection to a 2.5 inch SATA hard disk. The assembled CloudShell is shown in the diagram below.
The ARM big.LITTLE technology is ideal for a home server in that when the cpu load is low, it uses the power efficient A7 core(s) and when the load is high, it switches to use the high performance A15 core(s). It may use 1 core, more than 1 core or all cores at the same time depending on the load. This means energy saving in the long run.
This article is not an Odroid XU4 review. For that you can read this in-depth review here. This article describes my experience in using this wonderful little device. Continue reading Using Odroid XU4 CloudShell as My Home Server