NILFS-TUNE

Section: Maintenance Commands (8)

Updated: Apr 2014

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NAME

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

SYNOPSIS

nilfs-tune [options] device

DESCRIPTION

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.

OPTIONS

-f

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.

-l

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:

block_count: 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.

-U UUID

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".

-h

Display help message and exit.

AUTHOR

Jiro SEKIBA <jir at unicus.jp>

AVAILABILITY

nilfs-tune is part of the nilfs-utils package and is available from https://nilfs.sourceforge.io.