The Virtualization Cookbook for SLES 10 SP2 - z/VM - IBM

14.1.1 Using the INDICATE command
z/VM has some basic commands such as INDICATE. There are many INDICATE parameters that
can be included as command line options. Use the command HELP INDICATE for a basic
understanding and then press F11 for help on each parameter.
INIDICATE LOAD
If no parameter is specified INDICATE LOAD is the default option. There are two flavors of this,
depending on whether the issuing user ID has privilege class G or class E. Class G users can
use INDICATE to display recent contention for system resources, display environment
characteristics and measurements of resources used by their virtual machine.
The output from user ID with class E privilege (e.g. MAINT, OPERATOR) is shown here. The lines
are number for clarity of the description that follows:
==> ind load
1 AVGPROC-038% 03
2 XSTORE-000021/SEC MIGRATE-0001/SEC
3 MDC READS-000068/SEC WRITES-000001/SEC HIT RATIO-099%
4 PAGING-0031/SEC STEAL-000%
5 Q0-00006(00000) DORMANT-00357
6 Q1-00001(00000) E1-00000(00000)
7 Q2-00001(00000) EXPAN-002 E2-00000(00000)
8 Q3-00034(00000) EXPAN-002 E3-00000(00000)
9
10 PROC 0000-038% PROC 0001-038%
11 PROC 0002-038%
12
13 LIMITED-00000
The INDICATE LOAD command gives a snapshot of current system performance. Except for the
counts of virtual machines in various queues and the limited list, the values you see here are
a smoothed average over the past 4 minutes. Areas where z/VM performance analysts tend
to focus are the following:
► AVGPROC on line 1 gives the overall processor utilization, 38% in this example. The number
following it is the number of on-line processors, 3 in this example. The individual processor
utilization is shown on lines 10 and 11. Take a glance at these to see if they are somewhat
balanced. There are cases where an imbalance is okay. This would include very low
utilization scenarios or cases where there are not enough users ready to run virtual
processors to keep the physical processors busy. One of the processors will be a Master,
all of the others Alternate, and some imbalance may result from performing these
functions. Line 2 describes paging to expanded storage. Most z/VM systems on z9 class
machines can sustain several 1000s of this type of paging operations a second without
any problems. z10 class machines will perform even better. The MIGRATE rate is the
number of pages per second being moved from expanded storage out to paging space on
DASD. A healthy system will have a MIGRATE rate significantly lower than the XSTORE rate,
probably being measures in 100s rather than 1000s. The higher values seen tend to build
up over time, and are sustained over periods of intense system activity, however, there
are times the MIGRATE value may spike for brief periods of time.
► Minidisk cache (MDC) statistics are given on the third line. The effectiveness of MDC can be
judged by the combination of the READS rate and the HIT RATIO. If both are high, then a
large number of physical I/Os are avoided due to the MDC feature. For a system which
has an appreciably high I/O rate, composed of reads plus writes, and a high proportion of
reads, and a good hit ratio for those reads (tending to 90% or greater), the real, physical
I/O avoidance can be very high, this author has seen the avoidance as high as 50% in
some cases. Conversely, however, a high HIT RATIO with a low value for the READS rate
224 The Virtualization Cookbook for RHEL 6