FS_USAGE
Section: User Commands (1)
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BSD mandoc
Mac OS X
NAME
fs_usage
- reports system calls and page faults related to filesystem activity
in real-time.
SYNOPSIS
fs_usage [-e] [-w] [ pid|cmd [pid|cmd] ...]
DESCRIPTION
fs_usage
presents an ongoing display of system call usage
information pertaining to filesystem activity. By default
this includes all system processes except the running
fs_usage process,
Terminal, telnetd, sshd, rlogind, tcsh, csh and sh.
These defaluts can be overridden such that output is limited to
include or exclude a list of processes specified by the user.
The output presented by
fs_usage
is formatted according to the size of your window.
A narrow window will display fewer columns of data.
Use a wide window for maximum data display. You may
override the window formatting restrictions by
forcing a wide display with the
-w
option. In this case, the data displayed will wrap
when the window is not wide enough.
The options are as follows:
- -e
-
Specifying the
-e
option generates output that excludes sampling
of the running fs_usage tool. If a list of
process ids or commands is also given, then
those processes are also excluded from the sampled
output.
- -w
-
Specifying the
-w
option forces a wider, more detailed output,
regardless of the window size.
- pid | cmd
-
The sampled data can be limited to a list of process
ids or commands. When a command name is given, all
processes with that name will be sampled. Using the
-e
option has the opposite effect, excluding sampled data
relating to the given list of process ids or commands.
If "/tmp/FileTracing" is present when a Carbon Application
is launched, then the high level Carbon FileManager
calls will be displayed bracketing the system calls that they
are built on.
The data columns displayed are as follows:
- TIMESTAMP
-
TOD when call occurred. Wide mode will
have millesecond granularity.
- CALL
-
the name of the filesystem call or page-in.
- FILE DESCRIPTOR
-
Of the form F=x, x is a file descriptor. Depending
on the type of system call, this will be either
an input value or a return value.
- BYTE COUNT
-
Of the form B=x, x is the number of bytes requested by the call.
- [ERRNO]
-
On error, the errno is displayed in brackets.
- PATHNAME
-
Pathname of the file accessed (up to the last 28 bytes).
- FAULT ADDRESS
-
Of the form A=0xnnnnnnnn, where 0xnnnnnnnn is the
address being faulted.
- TIME INTERVAL(W)
-
The elapsed time spent in the system call.
A 'W' after the elapsed time indicates
the process was scheduled out during
this file activity. In this case, the elapsed
time includes the wait time.
- PROCESS NAME
-
The process that made the system call.
SAMPLE USAGE
fs_usage -w telnetd
fs_usage
will report file system usage data for all
instances of processes named telnetd. Maximum
data output will be displayed in the window.
SEE ALSO
top(1)
sc_usage1
latency(1)
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- SAMPLE USAGE
-
- SEE ALSO
-
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Time: 04:29:48 GMT, April 24, 2025