Example 5 – HP PolyServe Software User Manual

Page 12

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Advanced I/O Monitoring

9

• Large Data. I/O transfers of sizes greater than 16K are reported under this

column. Generally, these will be full table scan driven (e.g., db file scattered
read or direct path read,direct path write).

• OLG. This column is for Online Redo Log I/O activity (e.g.,

LGWR

).

• ALG. This column is for Archived log activity (e.g.,

ARCH

).

• Sort. This column tracks I/O operations to/from temporary tablespaces (e.g.,

sorting).

• Other. All activity not fitting the other types is tracked under this column (e.g.,

control file writes, etc.).

Figure 4 contains an example of the -s file option/argument pair.

Figure 4

Example 5

Question: At fixed times during the week, the majority of my OLTP users are
limited to nodes 1 and 2. Nodes 5 and 6 have much more memory and are
configured for most of the large DSS and reporting activity. How can I monitor to
ensure that the very heavy I/O workload intended to run on nodes 5 and 6 is not
impacting I/O service times on the OLTP nodes?

Answer. Once again, the -I option should be used. Figure 5 depicts a perfect
example of this usage. The

BENCH5

and

BENCH6

instances are periodically

performing a burst of asynchronous I/O up to 50MB/sec, yet the

BENCH1

and

BENCH2

instances are not showing substantial increase in I/O service times.

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