The restart of a UNIX server call initialization scripts to start processes and daemons. Every platform has a unique directory structure and follows a method to implement server startup sequence. In Linux platform (prior to Linux 6), initialization scripts are started by calling scripts in the /etc/rcX.d directories, where X denotes the run level of the UNIX server. Typically, Clusterware is started at run level 3. For example, ohasd daemon started by /etc/rc3.d/S96ohasd file by supplying start as an argument. File S96ohasd is linked to /etc/init.d/ohasd.
S96ohasd -> /etc/init.d/ohasd /etc/rc3.d/S96ohasd start # init daemon starting ohasd.
Similarly, a server shutdown will call scripts in rcX.d directories, for example, ohasd is shut down by calling K15ohasd script:
K15ohasd -> /etc/init.d/ohasd /etc/rc3.d/K15ohasd stop #UNIX daemons stopping ohasd
In Summary, server startup will call files matching the pattern of S* in the /etc/rcX.d directories. Calling sequence of the scripts is in the lexical…
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