Figure 8-14. Shown is a simple log writer background process IO script that will produce both IO operations per second (IOPS) and MB/s. The script takes a single argument of the interval gathering time.

Figure 8-15. Shown is the output from the script shown in Figure 8-14 with a gathering interval of 60 seconds. During the 1-minute interval, on average, the log writer wrote 1.6 IO operations each second, or 1.6 IOPS, and it wrote an average of 4.070 MB/s.

While it is useful and relatively simple to collect only the log writer IO statistics, the IO subsystem administrators may want to see a fuller perspective. Through only Oracle's v$sysstat view, all Oracle read and write requirements can be determined for both the background processes and server processes, broken out by reads and writes, and also by IOPS and MB/s. Figure 8-16 shows the output from OraPub's OSM script iosumx.sql. The log writer portion of the script gathers the same information as shown in Figure 8-14.