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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 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.

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

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

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 2005-06-19