Hey, another issue with high CPU usage. To start from the begining, I had problem with PC becoming non responsive. Task Manager was showing CPU 100%, Memory 100%, Swap file 100%. I couldn't get the machine to responsed, so I did a hard reboot. After that it restarted, but reported a Smart Hard disk error.
I performed a clone of the hard drive, which was planned in any case as a backup. Running Taskmanager again, still showed a surprisingly high cpu uasage. It was the Taskmanager itself that appeared to be reporting the highest usage. I checked the web and found a lot of reports of high cpu usage from Taskmanager, with suggestion for alternatives. I closed down Taskmanager and just used the cli command TOP. This seemed to improve cpu usage considerably, down to 13%. I was still surprised about 13% when really the system shouldm't have been doing much. TOP showed me it was fuzzyflakes (screensaver) that was responsible. A little while later, the other screensaver kicked in, and the cpu usage went higher. I decided to shutdown the gui desktop, as it wasn't really needed on my server.
There are 10 types of people; those who understand binary and those who don't.
I had a problem recently after moving furniture around, my web server lost it's connection and eth0 was missing. After spending a bit of time mucking around with trying to reconfigure ip address etc, I eventually realised that the problem was with the persistent rules (/etc/udev/rules.d/70-persistent-net.rules) file must have been currupted (bumped the power out). When this file was recreated, it was not set with same mac address. I edited the mac address in the persistent rules file to match how it had previously been set as that was what my router was expecting.
Before the above though, my HDD had been corrupted (shut down unexpectedly) and was booting into BusyBox. I had to run fsck to repair the disk. This needs to be done while not mounted. Booted system using usb, then run fsck repair.
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