nilfs-tune man page

nilfs-tune — adjust tunable file system parameters on NILFS file system


nilfs-tune [options] device


nilfs-tune is a utility to modify tunable file system parameters on NILFS2 file system in device.

This command is valid for inactive NILFS2 file systems. Modifying active mounts may cause severe damage.



Force to modify even the specified file system is mounted.

-i interval

Set the commit interval of segment.

-m block-max

Set the threshold of the data amount of the segment construction.


List the contents of the file system superblock, including the current values of the parameters that can be set via this program.

-L volume-label

Set the volume label of the file system.  NILFS2 file system labels can be at most 80 bytes long.  If volume-label is longer than 80 bytes, nilfs-tune will truncate it.  The volume label can be used mount(8) and /etc/fstab(5) (and possibly others) by specifying LABEL=volume-label instead of a block special device name like /dev/sda5.

-O [^]feature[,...]

Set or clear the indicated filesystem features (options) in the filesystem. More than one filesystem feature can be cleared or set by separating features with commas.  Filesystem features prefixed with a caret character ('^') will be cleared in the filesystem's superblock; filesystem features without a prefix character will be added to the filesystem.

The following filesystem feature can be set or cleared using nilfs-tune:


Enable block count per checkpoint. After setting this option, fsck should be run on the filesystem to make the counts right, but no fsck tool is available yet, sorry.


Set the universally unique identifier (UUID) of the file system to UUID. The format of the UUID is a series of hex digits separated by hyphens, like this: "c1b9d5a2-f162-11cf-9ece-0020afc76f16".


Display help message and exit.


Jiro SEKIBA <>


nilfs-tune is part of the nilfs-utils package and is available from

See Also

nilfs(8), lscp(1), chcp(8), mkcp(8), rmcp(8).

Referenced By

chcp(8), lscp(1), mkcp(8), nilfs(8), nilfs-resize(8), rmcp(8).

Apr 2014 nilfs-utils version 2.2