Ext3 File System Corruption and Its Recovery

Ext3 file system is a journaled file system which is mostly used by the Linux kernel. It is the default file system for many Linux distributions. Important file system in ext3 file system is journal., hence called as journaled file system. Major drawback with ext3 file system is that it doesn’t support checksumming while writing to the journal and due to that the file system gets closer to corruption and need of Linux data recovery is felt. Checksumming is generally defined as an error detection technique if the file is corrupted. But the main cause is that the ext3 doesn’t support this feature, recovering from corrupt journal can damage all metadata information of file system.

System crash is recoverable if the file system in-use supports journaling. But in ext3, if the mounting options in /etc/fstab don’t include barrier=1 as enabled plus hard drive is performing out-of-order write caching and system gets crashed, ext3 catches risk of corruption.

This barrier feature is disabled by default in all of the Linux distributions, except in open SUSE, and so these systems can lose data there is a crash. Also, if user tries to use the mount option for ex3, a warning is issued about barriers is not supported. In such conditions also the system gets crashed.

In all the above situation the required blocks could be written, if user commits transaction and system crashes, it will reboot. During this, log replays and incomplete disk writing will be carried out with damaged journal information. This cause into overwriting of normal data with that of damaged and hence file system gets corrupted. Data under these situations can be recovered with the help of linux recovery application. One best thing is that the successor of ext3 i.e. ext4 supports journal checksumming.

There are so many applications in market, available as Linux recovery software which can recover lost data from Linux systems with corrupt file systems. These data recovery linux applications can be used easily without any prior sound technical knowledge. These software are safe for recovering data as they are of read-only design.