Journalled recovery is similar to the recovery techniques used by data bases to recover to a consistent state after a crash. For the most part, this gets around the need to run file by file quality checks on the file system. Those checks can take unreasonable amounts of times for large file systems.
Journalling is said to have little impact on performance. Journalling is generally built in as one feature of a complex set of features. Since it is not a discrete add-on that can simply be disabled, it is not easily possible to determine what the performance impact of journalling itself really is.
The two best known Linux journalled file systems are ReiserFS and XFS. Other Journalled file systems include JFS, Ext3 and (maybe) Tux2. ReiserFS is supported by Linux Kernels.
Return To Index Copyright 1994-2002 by Donald Kenney.