IBM TotalStorage DS6000 Series: Performance Monitoring and Tuning

88 IBM TotalStorage DS6000 Series: Performance Monitoring and Tuning

Figure 4-1 Welcome to Disk Magic

4.1.4 Disk Magic for zSeries

In the following example to do a model for zSeries, we select General Project from the

Create New Project options in the panel above, and enter 1 as the Number of zSeries

Servers.

In this section we do an overview of the more relevant dialog panels that Disk Magic presents

when doing a zSeries modeling and we discuss what information to complete in those panels.

Here we start with a disk subsystem where the workload is currently running.

Hardware configuration

Figure 4-2 on page 89 shows the Disk Subsystem - DSS1 dialog window with the ESS F20

disk subsystem as an example. The General tab is used to enter hardware information like

the Hardware Type (that basically identifies the

base model machine), as well as the cache

and NVS size information. In this dialog panel, the number of

logical control units (LCUs)

within the disk subsystem is entered; if this is an existing ESS, then this would be the number

of CKD LSSs. The Parallel Access Volume box must be checked to indicate if aliases are

used for this ESS.

Chapter 4. Planning and monitoring tools 89

Figure 4-2 Disk Subsystem zSeries dialog

By clicking Hardware Details we open an ESS Configuration Details dialog window, shown in

Figure 4-3. This dialog window is used to provide further information about the disk

subsystem hardware configuration. The fields displayed in this dialog window will depend on

the hardware type (see Figure 4-2) that was initially selected. In this ESS F20 example, we

need to choose how many Host Adapters and Device Adapters are configured with the ESS.

Also we need to select the cache size. The NVS size is not selectable, because it is a fixed

size for the ESS.

The number of 8-packs will be calculated based on the number of logical volumes that will be

defined in the zSeries disk tab.

Figure 4-3 Configuration details

Interfaces panel

Figure 4-4 on page 90 shows the panel where you define the interface connections used

between the server and the disk subsystem. If Remote Copy is used, you should define the

90 IBM TotalStorage DS6000 Series: Performance Monitoring and Tuning

Remote Copy function used, the connection to the Remote Copy site, and the distance

between the Primary and Secondary site. Note that the distance here is defined in kilometers.

Figure 4-4 Interfaces panel zSeries

zSeries Disk panel

Select zSeries Disk to enter the disk characteristics:

򐂰 Type (Physical) of the Disk Drive Module (DDM)

– GB capacity of the DDM

– Speed of the DDM in RPM

򐂰 Type (Logical) volume: the 3380 or 3390 model type

򐂰 Enter either of the following:

– Count (Logical): the number of volumes or

– Size (GB): the total GB capacity in this group

zSeries workload

Figure 4-5 on page 91 is where you enter the workload characteristics of all the LCUs

associated to the ESS F20. There is a tab for every LCU defined in the General Panel. The

workload characteristics include:

򐂰 I/O Rate

򐂰 IOSQ Time

򐂰 Pending Time

򐂰 Disconnect Time

򐂰 Connect Time

򐂰 If Remote Copy is used, you can also define the percentage of the total workload that is in

a Remote Copy relationship.

Chapter 4. Planning and monitoring tools 91

The cache statistics also need to be entered to create a proper model of the workload. This

can be done by clicking CRR, RMF or CMF and then entering the cache statistics.

Figure 4-5 zSeries workload

Creating Base model

After all the workload characteristics have been entered, we can now create the Base model

for this particular configuration. Clicking Base will build the Base model, if the workload

characteristics are within the capabilities of the disk subsystem. If not, an error will be

presented with the reason the Base model could not be created. In this case, you could check

if the workload characteristics entered are correct. If this still does not solve the problem, you

can choose, for a z/OS system, a different RMF interval time to use for the model.

Merging multiple disk subsystems

In the case of a DS6000, you may want to merge several other disk subsystems onto one

DS6000. Figure 4-6 on page 92 illustrates two ESS F20s being merged onto one DS6800.

Right-click one of the ESSs, and click Merge option, then click Add to Merge Source

Collection and create New Target. This will create a new disk subsystem called Merge

Target1. Now right-click the second ESS and select Merge and Add to Merge Source

Collection.