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Manual Reference Pages  -  CMON (1)


cmon - Coda server monitor




cmon [ -a ] [ -t probeinterval ] server [ server ... ]


cmon probes the specified list of servers once every probeinterval seconds and reports on their status. If a server is down or unreachable, cmon tries to reestablish contact with it once every probeinterval seconds. It uses the curses(3) package for screen management and can be used on dumb terminals. Run cmon in a terminal emulator (like xterm(1)).

Some cmon data can be displayed in relative or absolute modes. In relative mode, data is reported with reference to the interval between the last two probes. In absolute mode, the accumulated value since initialization is reported. cmon can be toggled between absolute and real modes of presentation from the keyboard. Typing a will cause data to be presented in absolute mode. Typing r will present it in relative mode. A mode change will only take place at the next probe.


The command-line options are:
-a Report data in absolute mode.
-t Probe servers every probeinterval seconds. Default is 60.


The data reported by cmon is organized under four headings: TIM, CPU, RPC, and DSK.

The TIM data is as follows:
mon time at which this cmon process was created.
prob time at which the server was last probed.
succ time at which the server last responded to a probe.
up time at which the server process was started.
bind number of times contact was reestablished after a failed probe. A probe may fail due to server or network failures.
The CPU data is as follows:
sys Relative or absolute number of seconds of system CPU time used on the server.
user Relative or absolute number of seconds of user CPU time (regular or niced) used on the server.
util Relative or absolute number of system and user seconds divided by corresponding time of accumulation.
The RPC data is as follows:
conn Number of RPC connections.
wkst Number of workstations connected to server. Note that each instance of cmon shows up as a workstation.
call Relative or absolute number of RPC calls received.
pki Relative or absolute number of RPC packets received. Includes duplicates and other bogus packets. Also includes bulk transfer packets.
pko Relative or absolute number of packets sent. Includes retransmissions. Also includes bulk transfer packets.
byi Bytes corresponding to pki.
byo bytes corresponding to pko.
The DSK data is as follows:
max1 Identity and percent usage of most full disk partition on server. The identity is the name of mount point. Names longer than 5 characters are truncated to the first 3 characters, a $ character, and the last character.
max2 Identity and percent usage of second most full disk.
max3 Identity and percent usage of third most full disk.


If a server is down or unreachable, statisitics for it are reported as "???".

Relative data is undefined until two or more probes have been made. Such data is reported as "***" between the very first and second probes.


o Relative computations are just based on the difference between the two most recent probes. A smarter approach (especially for CPU utilization) would be to use some kind of weighted history.
o The display is optimized for maximum packing of information into a small screen area. It may be cryptic for a novice.
o No disk information is available about the root partition on a server.
o Will core dump if run in a window with fewer than 25 lines.
o No way to force a redisplay (eg ^L).


codacon(1), vutil(8), curses(3)


o M. Satyanarayanan, 1990, Created
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Coda Distributed File System CMON (1) 25 April 2005

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