system_cmds/fs_usage.tproj/fs_usage.1

   1 .\" Copyright (c) 2000, Apple Computer, Inc.  All rights reserved.
   2 .\"
   3 .Dd November 7, 2002
   4 .Dt FS_USAGE 1
   5 .Os "Mac OS X"
   6 .Sh NAME
   7 .Nm fs_usage
   8 .Nd report system calls and page faults related to filesystem activity in
   9 real-time
  10 .Sh SYNOPSIS
  11 .Nm fs_usage [-e] [-w] [-f mode] [-b] [-t seconds] [-R rawfile [-S start_time] [-E end_time]] [pid | cmd [pid | cmd] ...]
  12 .Sh DESCRIPTION
  13 The
  14 .Nm fs_usage
  15 utility presents an ongoing display of system call usage information
  16 pertaining to filesystem activity.
  17 It requires root privileges due to the kernel tracing facility it uses to
  18 operate.
  19 By default, the activity monitored includes all system processes except the
  20 running
  21 .Nm fs_usage
  22 process, Terminal, telnetd, telnet, sshd, rlogind, tcsh, csh, sh, and zsh.
  23 These defaults can be overridden such that output is limited to include or
  24 exclude a list of processes specified by the user.
  25 .Pp
  26 The output presented by
  27 .Nm fs_usage
  28 is formatted according to the size of your window.
  29 A narrow window will display fewer columns of data.
  30 Use a wide window for maximum data display.
  31 You may override the window formatting restrictions
  32 by forcing a wide display with the
  33 .Fl w
  34 option.
  35 In this case, the data displayed will wrap
  36 when the window is not wide enough.
  37 .Pp
  38 The options are as follows:
  39 .Bl -tag -width Ds
  40 .\" ==========
  41 .It Fl e
  42 Specifying the
  43 .Fl e
  44 option generates output that excludes sampling
  45 of the running fs_usage tool.
  46 If a list of process IDs or commands is also given,
  47 then those processes are also excluded from the sampled output.
  48 .\" ==========
  49 .It Fl w
  50 Specifying the
  51 .Fl w
  52 option forces a wider, more detailed output,
  53 regardless of the window size.
  54 .\" ==========
  55 .It Fl f
  56 Specifying the
  57 .Fl f
  58 option turns on output filtering based on the
  59 .Pa mode
  60 provided.
  61 Multiple filtering options can be specified.
  62 By default, no output filtering occurs.
  63 The supported modes are:
  64 .Pp
  65 .Pa  network
  66 Network-related events are displayed.
  67 .Pp
  68 .Pa filesys
  69 Filesystem-related events are displayed.
  70 .Pp
  71 .Pa pathname
  72 Pathname-related events are displayed.
  73 .Pp
  74 .Pa exec
  75 Exec and spawn events are displayed.
  76 .Pp
  77 .Pa diskio
  78 Disk I/O events are displayed.
  79 .Pp
  80 .Pa cachehit
  81 In addition, show cache hits.
  82 .\" ==========
  83 .It Fl b
  84 Specifying the
  85 .Fl b
  86 option annotates disk I/O events with BootCache info (if available).
  87 .\" ==========
  88 .It Fl t Ar seconds
  89 Specifies a run timeout in seconds.
  90 .Nm fs_usage
  91 will run for no longer than the timeout specified.
  92 .\" ==========
  93 .It Fl R Ar raw_file
  94 Specifies a raw trace file to process.
  95 .\" ==========
  96 .It Fl S Ar start_time
  97 If
  98 .Fl R
  99 is selected, specifies the start time in microseconds to
 100 begin processing entries from the raw trace file. Entries
 101 with timestamps before the specified start time will be
 102 skipped.
 103 .\" ==========
 104 .It Fl E Ar end_time
 105 If
 106 .Fl R
 107 is selected, specifies the ending time in microseconds to
 108 stop processing entries from the raw trace file.  Entries
 109 with timestamps beyond the specified ending time will be
 110 skipped.
 111 .\" ==========
 112 .It  pid | cmd
 113 The sampled data can be limited to a list of process IDs or commands.
 114 When a command name is given, all processes with that name will be sampled.
 115 Using the
 116 .Fl e
 117 option has the opposite effect,
 118 excluding sampled data relating to the given list
 119 of process IDs or commands.
 120 .El
 121 .Pp
 122 The data columns displayed are as follows:
 123 .Bl -tag -width Ds
 124 .Pp
 125 .It TIMESTAMP
 126 TOD when call occurred.
 127 Wide mode will have microsecond granularity.
 128 .It CALL
 129 The name of the network or filesystem related call, page-in, page-out,
 130 or physical disk access.
 131 .It FILE DESCRIPTOR
 132 Of the form F=x, x is a file descriptor.
 133 Depending on the type of system call,
 134 this will be either an input value or a return value.
 135 .It BYTE COUNT
 136 Of the form B=x, x is the number of bytes requested by the call.
 137 .It [ERRNO]
 138 On error, the errno is displayed in brackets.
 139 .It PATHNAME
 140 Pathname of the file accessed (up to the last 28 bytes).
 141 .It FAULT ADDRESS
 142 Of the form A=0xnnnnnnnn,
 143 where 0xnnnnnnnn is the address being faulted.
 144 .It DISK BLOCK NUMBER
 145 Of the form D=0xnnnnnnnn,
 146 where 0xnnnnnnnn is the block number
 147 of the physical disk block being read or written.
 148 .It OFFSET
 149 Of the form O=0xnnnnnnnn, where 0xnnnnnnnn is a file offset.
 150 .It SELECT RETURN
 151 Of the form S=x, x is the number of ready descriptors returned
 152 by the select() system call.
 153 If S=0, the time limit expired.
 154 .It TIME INTERVAL(W)
 155 The elapsed time spent in the system call.
 156 A
 157 .Sq Li W
 158 after the elapsed time indicates the process was scheduled out
 159 during this file activity.
 160 In this case, the elapsed time includes the wait time.
 161 .It PROCESS NAME
 162 The process that made the system call.  Wide mode will append the
 163 thread id to the process name (i.e Mail.nnn).
 164 .El
 165 .Pp
 166 .Sh SAMPLE USAGE
 167 .Pp
 168 fs_usage -w -f filesys Mail
 169 .Pp
 170 .Nm fs_usage
 171 will display file system related data
 172 for all instances of processes named Mail.
 173 Maximum data output will be displayed in the window.
 174 .Sh SEE ALSO
 175 .Xr dyld 1 ,
 176 .Xr latency 1 ,
 177 .Xr sc_usage 1 ,
 178 .Xr top 1