Ubuntu Linux by default uses the EXT3 file system and there are 3 journaling methods for EXT3 system.
- Journal Data Writeback
- Journal Data Ordered
- Journal Data
On default installation Ubuntu chooses “journal data ordered” and In data=ordered mode, ext3 only officially journals metadata it logically groups metadata and data blocks into a single unit called a transaction. When it want to write the new metadata out to disk, the associated data blocks are written first. data=ordered mode effectively solves the corruption problem found in data=writeback mode and most other journaled filesystems, and it is done without requiring full data journaling. In general, data=ordered ext3 filesystems perform slightly slower than data=writeback filesystems, but slightly faster than the full data journaling counterparts. To speed it up we’re going to change it to data=writeback system.
Posted by priyo 