Journaling file systems were created by IBM to ensure that all data on a certain drive had been catalogued correctly. Someone who has lost data due to a crash knows that it can be quite difficult to recover. The purpose of a JFS is to ensure that all the changes were logged correctly. The log that is created has every step included so that data may be rebuilt, and there is no corruption of the data because every step of its rebuilding is included in the system. There is a huge difference between what the JFS does and what a standard file recording system does. Someone who has implemented a JFS will find that their crashes are much less devastating, and they take far less time to recover from.
The Need For The JFS
The need for the JFS is apparent in any computer system that could crash. There are many programs that will only record data as a single block, and it could be lost in an instant due to a crash or loss of power. Recovering the data is not sequential because the metadata is not included, and the files are often corrupted because they were not put back together in the right way. The JFS uses the information that was recorded during the creation of the content to build each file properly. This is a much faster way to recover from the loss of power or a crash, and it ensure that someone who has lost files may be confident that the corruption of the file will not happen. This is especially important when recording data for a secure system that could lose power. The servers that use a JFS are sure to recover their data much faster simply due to the fact that the JFS has been included.
Hiding Away The Journal
The beauty of a journaling system is that the journal will be placed somewhere that is completely separate from the files that it has recorded. The journal may be recovered because it has been sent to this hidden location, and there are many instances in which files are saved because this hidden location is found only after a crash. The person who wants to have a JFS included in their system must understand that special coding is required to create a JFS. The JFS will take down all the metadata that is used to record every keystroke on the computer or server. All that information will be used to create new files, and it is quite important that all information saved to the system is save from corruption because the JFS will use every bit of that data to rebuild the drive if it is ever lost.