Partitions are the logical division of a physical device. Numerous partition types are supported under Linux.
A file system is mounted on a mount point in Linux. The root file system is mounted at the root of the file system hierarchy and referred to as /.
The popular ext2 file system is mature and fast, and is often found on embedded and other Linux systems such as Red Hat and the Fedora Core series.
The ext3 file system adds journaling on top of the ext2 file system, for better data integrity and system reliability.
ReiserFS is another popular and high-performance journaling file system found on many embedded and other Linux systems.
JFFS2 is a journaling file system optimized for use with Flash memory. It contains Flash-friendly features such as wear leveling for longer Flash memory lifetime.
cramfs is a read-only file system perfect for small-system boot ROMs and other read-only programs and data.
NFS is one of the most powerful development tools for the embedded developer. It can bring the power of a workstation to your target device. Learn how to use NFS as your embedded target's root file system. The convenience and time savings will be worth the effort.
Many pseudo file systems are available on Linux. A few of the more important ones are presented here, including the proc file system and sysfs.
The RAM-based tmpfs file system has many uses for embedded systems. Its most significant improvement over traditional ramdisks is the capability to resize itself dynamically to meet operational requirements.
9.11.1. Suggestions for Additional Reading
"Design and Implementation of the Second Extended Filesystem" Rémy Card, Theodore Ts'o, and Stephen Tweedie First published in the Proceedings of the First Dutch International Symposium on Linux Available on http://e2fsprogs.sourceforge.net/ext2intro.html
"A Non-Technical Look Inside the EXT2 File System" Randy Appleton www.linuxgazette.com/issue21/ext2.html
Whitepaper: Red Hat's New Journaling File System: ext3 Michael K. Johnson www.redhat.com/support/wpapers/redhat/ext3/
ReiserFS Home Page www.namesys.com/
"JFFS: The Journaling Flash File System" David Woodhouse http://sources.redhat.com/jffs2/jffs2.pdf
README file from cramfs project Unsigned (assumed to be the project author) http://sourceforge.net/projects/cramfs/
NFS home page http://nfs.sourceforge.net
The /proc file system documentation www.tldp.org/LDP/lkmpg/2.6/html/c712.htm
File System Performance: The Solaris OS, UFS, Linux ext3, and ReiserFS A technical whitepaper Dominic Kay www.sun.com/software/whitepapers/solaris10/fs_performance.pdf
