Linux Magazine: Journaling File Systems

“The file system is one of the most important parts of an
operating system. The file system stores and manages user data on
disk drives, and ensures that what’s read from storage is identical
to what was originally written. In addition to storing user data in
files, the file system also creates and manages information about
files and about itself. Besides guaranteeing the integrity of all
that data, file systems are also expected to be extremely reliable
and have very good performance.

“For the past several years, Ext2 has been the de facto file
system for most Linux machines. It’s robust, reliable, and suitable
for most deployments. However, as Linux displaces Unix and other
operating systems in more and more large server and computing
environments, Ext2 is being pushed to its limits. In fact, many now
common requirements–large hard-disk partitions, quick recovery
from crashes, high-performance I/O, and the need to store thousands
and thousands of files representing terabytes of data–exceed the
abilities of Ext2.

“Fortunately, a number of other Linux file systems take up where
Ext2 leaves off. Indeed, Linux now offers four alternatives to
Ext2: Ext3, ReiserFS, XFS, and JFS. In addition to meeting some or
all of the requirements listed above, each of these alternative
file systems also supports journaling, a feature certainly demanded
by enterprises, but beneficial to anyone running Linux. A
journaling file system can simplify restarts, reduce fragmentation,
and accelerate I/O. Better yet, journaling file systems make fscks
a thing of the past…”

Complete
Story