lssu(1) - f34

1LSSU(1)                     General Commands Manual                    LSSU(1)
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NAME

6       lssu - list usage state of NILFS2 segments
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SYNOPSIS

9       lssu [options] [device]
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DESCRIPTION

12       lssu  is  a  utility  for  displaying usage state of NILFS2 segments in
13       device, where a segment is contiguous lump of disk blocks and an  allo‐
14       cation unit of NILFS2 disk space.  When device is omitted, /proc/mounts
15       is examined to find a NILFS2 file system.
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17       This command will fail if the device has no active mounts of  a  NILFS2
18       file system.
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OPTIONS

21       -a, --all
22              Do not hide clean segments.
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24       -h, --help
25              Display help message and exit.
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27       -i index, --index=index
28              Skip index segments at start of input.
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30       -l, --latest-usage
31              Print usage status of the moment.
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33       -n lines, --lines=lines
34              List only lines input segments.
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36       -p period, --protection-period=period
37              Specify  protection  period.   This option is used when printing
38              usage status of the moment (with -l  option)  to  test  if  each
39              block  in segments is protected and is not reclaimable.  Option‐
40              ally, the period parameter may be suffixed by one of the follow‐
41              ing  units  designators: ´s´, ´m´, ´h´, ´d´,´w´,´M´, or ´Y´, for
42              seconds, minutes, hours, days, weeks, months, or years,  respec‐
43              tively.
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45       -V, --version
46              Display version and exit.
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FIELD DESCRIPTION

49       Every line of the lssu output consists of the following fields:
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51       SEGNUM Segment number.
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53       DATE   Creation date.
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55       TIME   Creation time.
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57       STAT   State of the segment.  It consists of the following flags:
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59              a      The  segment  is active, meaning that it is recently cre‐
60                     ated and cannot be reclaimed by the garbage collector.
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62              d      The segment is dirty, meaning that it is in use.
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64              e      The segment is erroneous, meaning that it has once caused
65                     an I/O error.  NILFS2 avoids allocating the segments with
66                     this flag.
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68              p (optional)
69                     The segment is protected, meaning that garbage collection
70                     for  the  segment  is  prevented  for  some  reason,  for
71                     instance, the protection period is not elapsed  from  its
72                     last  modified  time,  the  segment is pinned by the file
73                     system, or it is erroneous and unreclaimable, etc.   This
74                     flag is displayed when -l option is specified.
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76       NBLOCKS
77              Number of in-use blocks of the segment.
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79       NLIVEBLOCKS (optional)
80              Number  and ratio of in-use blocks of the moment.  This field is
81              displayed when -l option is specified.
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AUTHOR

84       Koji Sato
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AVAILABILITY

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