[patch] add sar command example to DB disk section of Manage best pra…

…ctices

docs/mas/manage/bestpractice.md

@@ -119,6 +119,30 @@ To measure disk performance on Linux use the `dd` command. The sample command be
 [db2inst1@c-db2wh-manage-db2u-0 - Db2U bludata0]$
 ```
 
+Use the [sar](https://linux.die.net/man/1/sar) command line tool to check for disk performance. The example below shows that disk `dev8-64` is reporting as 100% utilized and with a svctm of 677.48 milliseconds.
+
+```
+$ sar -d 1
+
+Average:          DEV       tps     rkB/s     wkB/s   areq-sz    aqu-sz     await     svctm     %util
+Average:    dev202-16      2.29     50.81      0.00     22.23      0.00      0.81      0.17      0.04
+Average:    dev202-112      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
+Average:     dev202-0     71.62      0.19   2717.52     37.95      0.26      3.64      0.15      1.09
+Average:    dev202-32     26.67      0.00    257.90      9.67      0.03      1.17      0.20      0.52
+Average:     dev253-0     59.57      0.00    257.90      4.33      0.10      1.64      0.10      0.59
+Average:       dev8-0      0.05      0.00      0.00      0.00      0.00      0.00      1.00      0.00
+Average:      dev8-16      0.05      0.00      0.00      0.00      0.00      0.00      1.00      0.00
+Average:     dev253-1      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
+Average:      dev8-32      0.05      0.00      0.00      0.00      0.00      1.00      1.00      0.00
+Average:     dev253-2      2.57      0.00     10.86      4.22      0.00      1.04      0.98      0.25
+Average:      dev8-48      2.62      0.00     10.86      4.15      0.00      0.96    381.85    100.01
+Average:      dev8-64      1.48      0.00     40.19     27.23      0.00      1.06    677.48    100.01
+Average:     dev253-3      1.43      0.00     40.19     28.13      0.00      1.20      0.73      0.10
+Average:      dev8-80      0.05      0.00      0.00      0.00      0.00      1.00      1.00      0.00
+```
+
+
+
 ### Network latency between app and db server
 
 Reducing network latency is key to optimizing performance. Confirm latency is below 50ms by conducting a ping test. For production env, strongly recommend keeping the latency below 10ms and having app and db server in the same network segment. In cloud deployment scenarios, ensure both the database and OpenShift cluster are located within the same region, with the possibility of being in the same availability zone (AZ). Utilize the ping command to evaluate and pinpoint latency issues.