This is a major stumbling block preventing widespread use of Linux as a database server, among other things.Journaling filesystems are superior to static filesystems when it comes to guaranteeing data integrity and even when it comes to flat-out filesystem performance.Replacing the ext2fs static filesystem with a journaling filesystem will ultimately be a big win for all Linux users.How Filesystems Work A filesystem stores data on your hard drive by determining where each file’s blocks (chunks of the file’s content) should be stored and by maintaining a table of the locations of those blocks.But what if the power supply and backup power fail on your server?Things could get ugly when you finally restart the system, run fsck to check and repair the filesystems and wait and wait and wait.Directory blocks contain a table associating a list of inode numbers with the names of the files and other directories stored in that directory.A file’s inode contains information describing the file.
(See Figure Three.) Suppose you are in the midst of updating a directory entry, and you have just modified 23 file entries in the fifth block of a giant directory. You may wish you did the next time the power goes out in your machine room.We explain what they do and walk you through installing the reiserfs journaling filesystem. Your machines and network run smoothly, you back things up, and everything is under control.The inode for lists three data blocks, which reside at disk locations 3110, 3111, and 3506.(See Figure Two.) The gaps between these blocks are indicative of fragmentation, probably because the data blocks between 31 were already allocated to other files.