This is the journalling version of the Second extended file system (often called ext3), the de facto standard Linux file system (method to organize files on a storage device) for hard disks. The journalling code included in this driver means you do not have to run e2fsck (file system checker) on your file systems after a crash. The journal keeps track of any changes that were being made at the time the system crashed, and can ensure that your file system is consistent without the need for a lengthy check. Other than adding the journal to the file system, the on-disk format of ext3 is identical to ext2. It is possible to freely switch between using the ext3 driver and the ext2 driver, as long as the file system has been cleanly unmounted, or e2fsck is run on the file system. To add a journal on an existing ext2 file system or change the behavior of ext3 file systems, you can use the tune2fs utility ("man tune2fs"). To modify attributes of files and directories on ext3 file systems, use chattr ("man chattr"). You need to be using e2fsprogs version 1.20 or later in order to create ext3 journals (available at <http://sourceforge.net/projects/e2fsprogs/>). To compile this file system support as a module, choose M here: the module will be called ext3.
The journal mode options for ext3 have different tradeoffs between when data is guaranteed to be on disk and performance. The use of "data=writeback" can cause unwritten data to appear in files after an system crash or power failure, which can be a security issue. However, "data=ordered" mode can also result in major performance problems, including seconds-long delays before an fsync() call returns. For details, see: http://ext4.wiki.kernel.org/index.php/Ext3_data_mode_tradeoffs If you have been historically happy with ext3's performance, data=ordered mode will be a safe choice and you should answer 'y' here. If you understand the reliability and data privacy issues of data=writeback and are willing to make that trade off, answer 'n'.
Extended attributes are name:value pairs associated with inodes by the kernel or by users (see the attr(5) manual page, or visit <http://acl.bestbits.at/> for details). If unsure, say N. You need this for POSIX ACL support on ext3.
Posix Access Control Lists (ACLs) support permissions for users and groups beyond the owner/group/world scheme. To learn more about Access Control Lists, visit the Posix ACLs for Linux website <http://acl.bestbits.at/>. If you don't know what Access Control Lists are, say N
Security labels support alternative access control models implemented by security modules like SELinux. This option enables an extended attribute handler for file security labels in the ext3 filesystem. If you are not using a security module that requires using extended attributes for file security labels, say N.