Display system call statistics by using the sar -c command.
$ sar -c 00:00:00 scall/s sread/s swrit/s fork/s exec/s rchar/s wchar/s 01:00:00 38 2 2 0.00 0.00 149 120 |
The following example shows output from the sar -c command.
$ sar -c SunOS balmyday 5.10 s10_51 sun4u 03/18/2004 00:00:04 scall/s sread/s swrit/s fork/s exec/s rchar/s wchar/s 01:00:00 89 14 9 0.01 0.00 2906 2394 02:00:01 89 14 9 0.01 0.00 2905 2393 03:00:00 89 14 9 0.01 0.00 2908 2393 04:00:00 90 14 9 0.01 0.00 2912 2393 05:00:00 89 14 9 0.01 0.00 2905 2393 06:00:00 89 14 9 0.01 0.00 2905 2393 07:00:00 89 14 9 0.01 0.00 2905 2393 08:00:00 89 14 9 0.01 0.00 2906 2393 08:20:00 90 14 9 0.01 0.01 2914 2395 08:40:01 90 14 9 0.01 0.00 2914 2396 09:00:00 90 14 9 0.01 0.01 2915 2396 09:20:00 90 14 9 0.01 0.01 2915 2396 09:40:00 880 207 156 0.08 0.08 26671 9290 10:00:00 2020 530 322 0.14 0.13 57675 36393 10:20:00 853 129 75 0.02 0.01 10500 8594 10:40:00 2061 524 450 0.08 0.08 579217 567072 11:00:00 1658 404 350 0.07 0.06 1152916 1144203 Average 302 66 49 0.02 0.01 57842 55544 |
The following table describes the system call categories that are reported by the -c option. Typically, reads and writes account for about half of the total system calls. However, the percentage varies greatly with the activities that are being performed by the system.
Field Name |
Description |
---|---|
scall/s |
The number of all types of system calls per second, which is generally about 30 per second on a system with 4 to 6 users. |
sread/s |
The number of read system calls per second. |
swrit/s |
The number of write system calls per second. |
fork/s |
The number of fork system calls per second, which is about 0.5 per second on a system with 4 to 6 users. This number increases if shell scripts are running. |
exec/s |
The number of exec system calls per second. If exec/s divided by fork/s is greater than 3, look for inefficient PATH variables. |
rchar/s |
The number of characters (bytes) transferred by read system calls per second. |
wchar/s |
The number of characters (bytes) transferred by write system calls per second. |