Extended File System

Extended File System (ext) is one of a series of native #202202060057. There are mainly three of the versions is still active: ext2, ext3 and ext4.

#Journaling

Note: Only ext3 and ext4 can access this feature

To enable journaling feature on ext2, see #Tuning.

Get Information

dumpe2fs allow us to obtain file system information such as turned on file system features, file system state, inode count, block count, last checked and check interval.

It can be used when the file system is mounted.

Tuning

tune2fs allow us to adjust the file system settings such as:

-j to add a journal (effectively turning ext2 into ext3)
-i to set the check interval for fsck
-c to set the maximum number of times the disk may be mounted without a check
-C to set the number of times the disk has been mounted
-m and -r to define reserved disk space in percentage or blocks for root

However, this must be done in an unmounted file system in order to prevent data corruption.

Debugging

debugfs allow us to debug the file system interactively. However, this must be done in an unmounted file system in order to prevent data corruption.

There are multiple commands that could be helpful:

stats to display information similar to dumpe2fs
stat to show the indoe information for a file or directory
lsdel to list deleted inodes
undelete to restore the file by referring to its inode number
write to extract a file from the file system

We could use regular commands such as cd, rm and touch in the debugging environment too.