Section: User Commands (1)
Updated: Apr 2014
lssu - list usage state of NILFS2 segments
is a utility for displaying usage state of NILFS2 segments in
, where a segment is contiguous lump of disk blocks and
an allocation unit of NILFS2 disk space. When device
is examined to find a NILFS2 file system.
This command will fail if the device has no active mounts of a
NILFS2 file system.
- -a, --all
Do not hide clean segments.
- -h, --help
Display help message and exit.
- -i index, --index=index
Skip index segments at start of input.
- -l, --latest-usage
Print usage status of the moment.
- -n lines, --lines=lines
List only lines input segments.
- -p period, --protection-period=period
Specify protection period. This option is used when printing usage
status of the moment (with -l option) to test if each block in
segments is protected and is not reclaimable. Optionally, the
period parameter may be suffixed by one of the following units
designators: 's', 'm', 'h', 'd','w','M', or 'Y', for
seconds, minutes, hours, days, weeks, months, or years, respectively.
- -V, --version
Display version and exit.
Every line of the lssu
output consists of the following fields:
State of the segment. It consists of the following flags:
The segment is active, meaning that it is recently created and cannot
be reclaimed by the garbage collector.
The segment is dirty, meaning that it is in use.
The segment is erroneous, meaning that it has once caused an I/O
error. NILFS2 avoids allocating the segments with this flag.
- p (optional)
The segment is protected, meaning that garbage collection for the
segment is prevented for some reason, for instance, the protection
period is not elapsed from its last modified time, the segment is
pinned by the file system, or it is erroneous and unreclaimable, etc.
This flag is displayed when -l option is specified.
Number of in-use blocks of the segment.
- NLIVEBLOCKS (optional)
Number and ratio of in-use blocks of the moment. This field is
displayed when -l option is specified.
is part of the nilfs-utils package and is available from