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Configuring RAM disk elements

Any files or directories that should exist in the ramdisk are configured with the RAM* and LINK* directives. These directives can be used to create writable files and directories in the RAM disk, and the LINK* directives can be used to essentially make any file or directory in the root filesystem writable by converting it into a link into /ram, the oneSIS RAM disk.

Figure: ram-based files with the RAM* directives.
\includegraphics[width=3in,keepaspectratio]{diagram1}

The RAMFILE directive creates an empty file in the RAM disk, and the RAMDIR directive creates an empty directory.

The LINKFILE directive also creates an empty file in the RAM disk, and the LINKDIR directive creates an empty directory. In addition the LINK* directives direct the mk-sysimage script to alter the corresponding files in the root filesystem to become symlinks to /ram.

Figure: links to ram-based files with the LINK* directives.
\includegraphics[width=5in,keepaspectratio]{diagram2}

Both sets of directives have their role. The mk-sysimage script creates the necessary links in the master image. rc.preinit creates the corresponding files and directories in the /ram at boot-time or after update-node boots a node.

File permissions and ownership are mirrored from the root image, but can be set explicitly for RAM* directives.


Subsections
next up previous contents
Next: Duplicating files into /ram Up: Configuration Previous: Specifying the RAM disk   Contents
root 2017-02-23