syncstat(1M)

NAME

     syncstat -  report  driver  statistics  from  a  synchronous
     serial link

SYNOPSIS

     /usr/sbin/syncstat [-c] device [interval]

DESCRIPTION

     The syncstat command reports the event statistics maintained
     by  a  synchronous serial device driver. The report may be a
     single snapshot of the accumulated totals, or  a  series  of
     samples  showing  incremental  changes.  Prior  to  these it
     prints the device name being used to query a particular dev-
     ice  driver,  along  with  a  number  indicating the channel
     number (ppa) under control of that driver.

     Event statistics are maintained by a driver for each  physi-
     cal  channel  that it supports. They are initialized to zero
     at the time the driver module is  loaded  into  the  system,
     which may be either at boot time or when one of the driver's
     entry points is first called.

     The  device argument is the name of the serial device as  it
     appears in the /dev directory.  For example,  zsh0 specifies
     the first on-board serial device.

     The following is a breakdown of  syncstat output:

     speed         The line speed the device has  been  set  to
                   operate  at. It is the user's responsibility
                   to make this value correspond to  the  modem
                   clocking  speed when clocking is provided by
                   the modem.
     ipkts         The total number of input packets.
     opkts         The total number of output packets.
     undrun        The number of transmitter underrun errors.
     ovrrun        The number of receiver overrun errors.
     abort         The number of aborted received frames.
     crc           The  number  of  received  frames  with  CRC
                   errors.
     isize         The average size (in bytes) of  input  pack-
                   ets.
     osize         The average size (in bytes) of output  pack-
                   ets.

OPTIONS

     -c    Clear the accumulated statistics for the device speci-
           fied.  This  may be useful when it is not desirable to
           unload a particular driver, or when the driver is  not
           capable of being unloaded.

     interval
           syncstat  samples  the  statistics   every    interval
           seconds  and  reports  incremental changes. The output
           reports line utilization for input and output in place
           of  average packet sizes.  These are the relationships
           between bytes transferred and the baud rate, expressed
           as  percentages. The loop repeats indefinitely, with a
           column heading printed every twenty lines for conveni-
           ence.

EXAMPLES

     Example 1: Sample output from the syncstat command:

     example# syncstat zsh0

     speed ipkts opkts undrun ovrrun abort crc isize osize
     9600  15716 17121   0      0      1    3   98    89

     example# syncstat -c zsh0

     speed ipkts opkts undrun ovrrun abort crc isize osize
     9600   0     0     0      0      0     0    0     0

     In the following sample output a new line of output is  gen-
     erated every five seconds:

     example# syncstat zsh0 5

     ipkts opkts undrun ovrrun abort crc iutil outil
     12    10      0     0      0     0   5%    4%
     22    60      0     0      0     0   3%    90%
     36    14      0     0      0     1   51%   2%

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWcsu                     |
    |_____________________________|_____________________________|

SEE ALSO

     syncinit(1M), syncloop(1M), attributes(5), zsh(7D)

DIAGNOSTICS

     bad interval: arg
           The argument  arg is expected to be  an  interval  and
           could not be understood.

     device missing minor device number
           The name  device does not end in a decimal number that
           can be used as a minor device number.

     baud rate not set
           The  interval option is being used and the  baud  rate
           on  the  device is zero. This would cause a divide-by-
           zero error when computing the line utilization statis-
           tics.

WARNINGS

     Underrun,  overrun,  frame-abort,  and  CRC  errors  have  a
     variety  of  causes.  Communication  protocols are typically
     able to handle such errors  and  initiate  recovery  of  the
     transmission  in  which the error occurred. Small numbers of
     such errors are not a significant problem  for  most  proto-
     cols.  However,  because the overhead involved in recovering
     from a link error can be much greater than  that  of  normal
     operation, high error rates can greatly degrade overall link
     throughput. High error rates are often caused by problems in
     the  link  hardware,  such  as cables, connectors, interface
     electronics or telephone lines. They may also be related  to
     excessive load on the link or the supporting system.

     The  percentages  for  input  and  output  line  utilization
     reported when using the  interval option may occasionally be
     reported as slightly greater than 100%  because  of  inexact
     sampling  times  and differences in the accuracy between the
     system clock and the modem clock. If the percentage  of  use
     greatly  exceeds  100%,  or never exceeds 50%, then the baud
     rate set for the device probably does not reflect the  speed
     of the modem.