e4defrag

What e4defrag is

e4defrag is a free, open-source Linux utility for defragmenting extent-based files on ext4 filesystems. It can target a regular file, a directory and its files, or a device mounted as ext4. Its aim is to give target files more contiguous blocks, which the manual associates with improved file access speed. The -c option reports fragmentation counts and a score without defragmenting; the score is printed only when the check is run as root. With -v, the utility prints errors and each file’s fragmentation count before and after defragmentation.

The utility checks that the filesystem is ext4 and reports an error for other filesystem types. It does not support swap files, files in lost+found, or files allocated in indirect blocks. A device or mount-point target excludes files belonging to another device’s mount point. Fragmented or insufficient free space can prevent improvement. Non-privileged users can run it on their own files, and it can run while another application uses a file, though shared memory and disk bandwidth may slow both.