NAMEtopio - display and update information about the top I/O processes
SYNOPSIStopio [-f] [-b bytes] [-c scalls] [-s samples] [-t interval]
DESCRIPTIONtopio may be used to monitor processes making the highest use of system
I/O resources, based on the number of I/O related system calls and number
of bytes read or written.
The options are as follows:
-b Specifies a threshold on how many bytes of I/O per second must be
performed by a process during the sampling interval to be considered
``important'' enough to be reported. bytes must be an integral value
and a k or m suffix is allowed for scaling by 1000 and 1000000
respectively. The default is 100000.
-f Generate plain text output, suitable for writing to a file. The
default is to produce a window that is periodically updated using
libcurses.
-c Specifies a threshold on how many read(2) or write(2) system calls
per second must be made by a process during the sampling interval to
be considered ``important'' enough to be reported. scalls must be an
integral value and a k or m suffix is allowed for scaling by 1000 and
1000000 respectively. The default is 50.
-s The argument samples defines the number of samples to be reported.
If -s is not specified, topio will sample and report continuously.
-t The default update interval may be set to something other than the
default 5 seconds. The interval argument follows the syntax
described in PCPIntro(1), and in the simplest form may be an unsigned
integer (the implied units in this case are seconds).
The output from topio is directed to standard output.
OUTPUT FORMAT
By default (without the -f option), topio runs in full screen mode and
the data displayed on the terminal is overwritten on each update. This
display consists of a heading showing some system identification
information, the process counts by state and system-wide I/O totals,
followed by the ``top'' I/O processes. The reported activity appears
under the following columns:
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TOPIO(1)TOPIO(1)
_________________________________________________________________
Column Meaning
________________________________________________________________
PID the process ID
________________________________________________________________
command up to 7 letters of the process' argv[0]
________________________________________________________________
user up to 7 letters of the user name of the process' UID
________________________________________________________________
write(2) calls made per second during the update
interval
wcall/s
________________________________________________________________
read(2) calls made per second during the update
interval
rcall/s
________________________________________________________________
write throughput during the update interval
wbyte/s
________________________________________________________________
read throughput during the update interval
rbyte/s
________________________________________________________________
average bytes per write(2) during the update
interval
wavelen
________________________________________________________________
average bytes per read(2) during the update
interval
ravelen
________________________________________________________________
|
|
|
All numbers (system call rates, data throughput and average I/O length)
appear as either unscaled values, or with a suffix of k or m to indicate
scaling by 1000 or 1000000 respectively.
topio displays the data about ``important'' processes in sorted order.
The sort is on either (wbyte/s + rbyte/s) (the default) or on (wcall/s +
rcall/s). For the full screen mode of output, pressing ``s'' will toggle
the sort keys.
For the full screen mode of output, pressing ``q'' will terminate topio.
Pressing any other key causes the display to be updated immediately.
EXAMPLES
Beyond the simple use of topio to produce an interactive display
periodically updated to show those processes exceeding the system call or
bandwidth limits in the last 5 seconds, the following examples are
illustrative of some other uses.
To see what I/O the daemons are doing on a ``quiet'' system, set the
thresholds to be very low:
$ topio-b 1 -s 1
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TOPIO(1)TOPIO(1)
To monitor high bandwidth users over time:
$ topio-b 2m -c 100 -s 4000 -f >my.logfile
SEE ALSOPCPIntro(1), top(1) and pmchart(1).
AUTHORS
The original version of topio was developed by Mark Portney and Brian
Sumner.
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