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My server stopped working (inaccessible through network) without any reason.

Traffic was normal before it happened, circa 20MBit/s, after restart everything was OK and server was running as usually. Nothing interesting found in log files, on 1170 binary zeroes (represent as ^@^@^@^@) in kernel.log and syslog files. Server is running ubuntu 16.04.5 with classic LAMP stack.

marked as duplicate by JdeBP, Jeff Schaller, Stephen Harris, Mr Shunz, Rui F Ribeiro Jan 12 at 17:07

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    Is the size of your kernel.log and syslog file a multiple of 4096? If yes, it was simply a filesystem corruption caused by the crash. The crash could have caused by anything, the most likely is a hardware failure or a nuclear explosion in a parallel minkowski Universe in the same spacetime location. Anyways a memtest would be highly useful. – peterh says reinstate Monica Jan 12 at 8:14

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