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%SECTION0{name=TheAppWebServerHangsORDevrandomHangs}% The =appWeb= server hangs *OR* /dev/random hangs Question:: I try to run the =appWeb= server, but it hangs, because read accesses to =/dev/random= hang forever. What's wrong? Answer:: Your configuration of the Linux kernel does not contain drivers that feed enough entropy for =/dev/random=. Often mouse or keyboard drivers are used for this purpose, so on an embedded system without such devices =/dev/random= may not provide enough random numbers for your application. Workaround:: As a quick workaround you can use =/dev/urandom= instead; i. e. try the following commands on your system: <verbatim> # cd /dev # rm -f random # ln -s urandom random </verbatim> Solution:: The correct solution for the problem is of course to feed sufficient entropy into =/dev/random=. To do so you can modify one or more appropriate device drivers on your system; for example if you know that there is sufficient traffic on network or on a serial port than adding =SA_SAMPLE_RANDOM= to the 3rd argument when calling the =request_irq()= function in your ethernet and/or serial driver(s) will cause the inter-interrupt times to be used to build up entropy for =/dev/random=.
14.3.28. How can I access U-Boot environment variables in Linux?
1. Abstract
14.3.30. Swapping over NFS
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