1syncstat(1M) System Administration Commands syncstat(1M)
2
6 syncstat - report driver statistics from a synchronous serial link
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9 /usr/sbin/syncstat [-c] device [interval]
10
13 The syncstat command reports the event statistics maintained by a syn‐
14 chronous serial device driver. The report may be a single snapshot of
15 the accumulated totals, or a series of samples showing incremental
16 changes. Prior to these it prints the device name being used to query a
17 particular device driver, along with a number indicating the channel
18 number (ppa) under control of that driver.
19 Event statistics are maintained by a driver for each physical channel
22 that it supports. They are initialized to zero at the time the driver
23 module is loaded into the system, which may be either at boot time or
24 when one of the driver's entry points is first called.
25 The device argument is the name of the serial device as it appears in
28 the /dev directory. For example, zsh0 specifies the first on-board
29 serial device.
30 The following is a breakdown of syncstat output:
33 speed The line speed the device has been set to
38 operate at. It is the user's responsibility
39 to make this value correspond to the modem
40 clocking speed when clocking is provided by
41 the modem.
42 ipkts The total number of input packets.
43 opkts The total number of output packets.
44 undrun The number of transmitter underrun errors.
45 ovrrun The number of receiver overrun errors.
46 abort The number of aborted received frames.
47 crc The number of received frames with CRC
48 errors.
49 isize The average size (in bytes) of input pack‐
50 ets.
51 osize The average size (in bytes) of output pack‐
52 ets.
53
56 -c Clear the accumulated statistics for the device specified.
57 This may be useful when it is not desirable to unload a
58 particular driver, or when the driver is not capable of
59 being unloaded.
60 interval syncstat samples the statistics every interval seconds and
63 reports incremental changes. The output reports line uti‐
64 lization for input and output in place of average packet
65 sizes. These are the relationships between bytes trans‐
66 ferred and the baud rate, expressed as percentages. The
67 loop repeats indefinitely, with a column heading printed
68 every twenty lines for convenience.
69
72 Example 1 Sample output from the syncstat command:
73 example# syncstat zsh0
75 speed ipkts opkts undrun ovrrun abort crc isize osize
78 9600 15716 17121 0 0 1 3 98 89
79 example# syncstat -c zsh0
83 speed ipkts opkts undrun ovrrun abort crc isize osize
85 9600 0 0 0 0 0 0 0 0
86 In the following sample output a new line of output is generated every
91 five seconds:
92 example# syncstat zsh0 5
95 ipkts opkts undrun ovrrun abort crc iutil outil
97 12 10 0 0 0 0 5% 4%
98 22 60 0 0 0 0 3% 90%
99 36 14 0 0 0 1 51% 2%
100
104 See attributes(5) for descriptions of the following attributes:
105 ┌─────────────────────────────┬─────────────────────────────┐
110 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
111 ├─────────────────────────────┼─────────────────────────────┤
112 │Availability │SUNWcsu │
113 └─────────────────────────────┴─────────────────────────────┘
114
116 syncinit(1M), syncloop(1M), attributes(5), zsh(7D)
117
119 bad interval: arg
120 The argument arg is expected to be an interval and could not be
122 understood.
123 device missing minor device number
126 The name device does not end in a decimal number that can be used
128 as a minor device number.
129 baud rate not set
132 The interval option is being used and the baud rate on the device
134 is zero. This would cause a divide-by-zero error when computing the
135 line utilization statistics.
136
139 Underrun, overrun, frame-abort, and CRC errors have a variety of
140 causes. Communication protocols are typically able to handle such
141 errors and initiate recovery of the transmission in which the error
142 occurred. Small numbers of such errors are not a significant problem
143 for most protocols. However, because the overhead involved in recover‐
144 ing from a link error can be much greater than that of normal opera‐
145 tion, high error rates can greatly degrade overall link throughput.
146 High error rates are often caused by problems in the link hardware,
147 such as cables, connectors, interface electronics or telephone lines.
148 They may also be related to excessive load on the link or the support‐
149 ing system.
150 The percentages for input and output line utilization reported when
153 using the interval option may occasionally be reported as slightly
154 greater than 100% because of inexact sampling times and differences in
155 the accuracy between the system clock and the modem clock. If the per‐
156 centage of use greatly exceeds 100%, or never exceeds 50%, then the
157 baud rate set for the device probably does not reflect the speed of the
158 modem.
159SunOS 5.11 9 Mar 1993 syncstat(1M)