What is a Journaling File System?

A journaling file system is a special technology used in computer file systems that maintain a serial log of updates or system changes made to bitmaps and directories. Directories can roughly be compared to manila folders in which data such as electronic files and images are stored on a disk. System updates are actually recorded to the serial log before any permanent changes are made to the original record of the disk. If there is a sudden crash during the "writing" of updates to the serial log, data integrity is not destroyed; rather, the system instantly reverts back to the state it was in before the crash took place.

Almost all operating systems can handle the technology of a journaling file system, which has been around since the 1980s. Servers, however, not personal computers (PCs), tend to be the platforms on which this technology is needed and is widely employed. During a power outage, an improper shutdown or a crash, data that has not been saved could be permanently lost without the advantages of a journaling file system that enables the recovery of unsaved data and its automatic storage in a target location. It is easy to see how this type of technology is vital in data processing environments where almost all operations are considered to be critical to the company.

There are options with a journaling file system that are studied and chosen by the people in charge of setting up enterprise-level computing environments such as networks. For example, these network administrators and engineers, depending on the specific journaling file system selected, have the option to indicate how much data is journaled, because some time is required for a journaled file to be read and recovered. They have to consider speed in performance as well as data integrity and must choose the best option to allow for as close to an ideal balance as possible.

The use of a journaling file system usually is not necessary on a PC. A well-planned backup system generally is the best method for protecting data integrity. People who use their PCs to run a home-based business, however, might want to consider using a journaling file system, just in case. Many operating systems that are completely free of charge offer the option to use the sophisticated technology of a journaling file system. Home-based business generally do not process the heavy loads of data that large corporations or organizations do, so, they rarely notice any lag in performance.