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@unicus.jp>

AVAILABILITY

       nilfs-tune is part of the nilfs-utils package and is available from http://www.nilfs.org.

SEE ALSO

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