Measuring DAFS performance

About measuring DAFS performance

To measure the performance of the DAFS service, you use the sysstat -d and dafs stats commands. The command syntax and functions provided are as follows:

The sysstat -d command reports aggregated filer performance statistics, including current CPU utilization; I/O usage for network, disk, and tape; and DAFS statistics with the DAFS default output format.
The dafs stats command gathers statistics on individual DAFS server operations for a specified time interval. During the time interval, the following statistical information is reported for each operation:
- The number of count operations that occurred
- The percentage of total operations represented
- The rate (operations per second) of the operation
- The time per operation in milliseconds

For more information, see the man pages for na_sysstat(1) and na_dafs(1).

Displaying filer statistics

To display filer statistics that include the DAFS statistics with the DAFS default output format, complete the following step.

Step	Action
1	At the filer command line, enter the following command: sysstat -d Result The display shows the filer statistics, including the DAFS operations (in place of the HTTP operations). Example: sysstat -d: CPU NFS CIFS DAFS Net kB/s Disk kB/s Tape kB/s Cache in out read write read write age 8% 0 0 2395 316 9930 8 0 0 0 51 8% 0 0 2385 315 9894 8 0 0 0 51 Note When invoked with no arguments, `sysstat` prints a new line of statistics every 15 seconds. Press Ctrl-C or set the interval count (`-c`) to stop the `sysstat` reporting. The `sysstat -x` option displays the extended format output.

Step

Action

At the filer command line, enter the following command:

sysstat -d

Result

The display shows the filer statistics, including the DAFS operations (in place of the HTTP operations).

Example:

sysstat -d:

CPU NFS CIFS DAFS  Net kB/s   Disk kB/s   Tape kB/s Cache

                    in   out   read write read write  age

8%  0   0    2395 316  9930   8     0    0     0    51

8%  0   0    2385 315  9894   8     0    0     0    51

Note
When invoked with no arguments, sysstat prints a new line of statistics every 15 seconds. Press Ctrl-C or set the interval count
(-c) to stop the sysstat reporting. The sysstat -x option displays the extended format output.

Gathering DAFS statistics only

To gather DAFS server operation statistics over a specified time interval, complete the following steps.

Step	Action
1	At the filer command line, enter the following command: dafs stats start Result The filer begins gathering statistics about the DAFS service. This command enables statistics gathering only and no statistics are displayed. Note The time interval is determined by the elapsed time between entering the `dafs stats start` command and a `dafs stats stop` command. If you start gathering statistics and then enter the `dafs stats list -z` command, the statistics counters are reset to zero. In this case, the time interval is the elapsed time between resetting the counters to zero and entering the `dafs stats stop` command. Example: filer> dafs stats start filer>
2	To view DAFS statistics as they are gathered, enter the following command at the filer command line: dafs stats list Result The display shows the statistics for the elapsed time between entering the `dafs stats start` command and the `dafs stats list` command. Note This command displays an intermediate result. Statistics continue to be gathered until the `dafs stats stop` command is run. You can zero the statistics counters with the `-z` option. For more information, see the na_dafs(1) man page. Example: filer> dafs stats list DAFS Statistics, gathered for 23 seconds, ops 38439 Operation Count Percent Ops/sec Msec/ op --------- ------- ------- ------- ------ Client Connect-Authenticate 1 0 0 1 Register Credentials 1 0 0 2 Get root handle 1 0 0 4 Lookup 2 0 0 1 Open 1 0 0 1 Read Inline 38431 99 1670 2 Remove 1 0 0 2 Write Inline 1 0 0 1 In this example, a list of DAFS statistics is displayed. A total of 23 seconds have elapsed since the gathering of DAFS statistics began.
3	To stop the statistics gathering, enter the following command at the filer command line: dafs stats stop Result The display shows the statistical results for the elapsed time between entering the `dafs stats start` command and the `dafs stats stop` command. If you reset the statistics counters to zero with the `dafs stats list -z` command, then the results are for the elapsed time between resetting the counters and entering the `dafs stats stop` command. Example filer> dafs stats stop DAFS Statistics, gathered for 31 seconds, ops 56483 Operation Count Percent Ops/sec Msec/ op --------- ------ ------- ------- ---- Client Connect-Authenticate 1 0 0 1 Register Credentials 1 0 0 2 Get root handle 1 0 0 4 Lookup 2 0 0 1 Open 1 0 0 1 Read Inline 56475 99 1821 2 Remove 1 0 0 2 Write Inline 1 0 0 1 In this example, the statistics gathering has ended and the final results are displayed. A total of 31 seconds elapsed for gathering statistics.

Step

Action

At the filer command line, enter the following command:

dafs stats start

Result

The filer begins gathering statistics about the DAFS service. This command enables statistics gathering only and no statistics are displayed.

Note
The time interval is determined by the elapsed time between entering the dafs stats start command and a dafs stats stop command. If you start gathering statistics and then enter the dafs stats list -z command, the statistics counters are reset to zero. In this case, the time interval is the elapsed time between resetting the counters to zero and entering the dafs stats stop command.

Example:

filer> dafs stats start

filer>

To view DAFS statistics as they are gathered, enter the following command at the filer command line:

dafs stats list

Result

The display shows the statistics for the elapsed time between entering the dafs stats start command and the dafs stats list command.

Note
This command displays an intermediate result. Statistics continue to be gathered until the dafs stats stop command is run. You can zero the statistics counters with the -z option. For more information, see the na_dafs(1) man page.

Example:

filer> dafs stats list

DAFS Statistics, gathered for 23 seconds, ops 38439

               Operation   Count   Percent  Ops/sec Msec/

op

                ---------  ------- ------- ------- ------

Client Connect-Authenticate   1       0        0      1

  Register Credentials        1       0        0      2

       Get root handle        1       0        0      4

                Lookup        2       0        0      1

                  Open        1       0        0      1

           Read Inline    38431      99     1670      2

                Remove        1       0        0      2

          Write Inline        1       0        0      1

In this example, a list of DAFS statistics is displayed. A total of 23 seconds have elapsed since the gathering of DAFS statistics began.

To stop the statistics gathering, enter the following command at the filer command line:

dafs stats stop

Result

The display shows the statistical results for the elapsed time between entering the dafs stats start command and the dafs stats stop command. If you reset the statistics counters to zero with the dafs stats list -z command, then the results are for the elapsed time between resetting the counters and entering the dafs stats stop command.

Example

filer> dafs stats stop

DAFS Statistics, gathered for 31 seconds, ops 56483

                     Operation Count  Percent Ops/sec Msec/

op

                     --------- ------ ------- ------- ----

Client Connect-Authenticate     1      0       0        1

       Register Credentials     1      0       0        2

            Get root handle     1      0       0        4

                     Lookup     2      0       0        1

                       Open     1      0       0        1

                Read Inline 56475     99    1821        2

                     Remove     1      0       0        2

               Write Inline     1      0       0        1

In this example, the statistics gathering has ended and the final results are displayed. A total of 31 seconds elapsed for gathering statistics.

Explanation of DAFS statistics

The dafs stats command gathers statistics on requests and operations, grouping them by the request. The statistics show the following:

Name of the request (operation)
Count of each operation
Percent of total operations
Number of operations per second over the elapsed time interval
Average time in milliseconds to execute an operation