covering several time intervals, and should include peak I/O rate, peak R/T, and peak (read and write) MB/sec throughput. Disk Magic will be enhanced to support the DS6000. Disk Magic provides insight when you are considering deploying remote technologies such as Metro Mirror. Confer with your sales representative for any assistance with Disk Magic.
Note: Disk Magic is available to IBM sales representatives and IBM Business Partners only.
8.6.2 Number of host ports
Plan to have an adequate number of host ports and channels to provide the required bandwidth to support your workload. The ports must also be balanced across the entire DS6000.
8.6.3 Remote copy
If the DS6000 is a primary disk system in a remote copy configuration, it will consume more resources, such as fibre channels ports, compared to a standalone disk system. Plan for the number of fibre ports.
8.6.4 Parallel Access Volumes (z/OS only)
Configuring the DS6000 with PAV will minimize or eliminate IOSQ delays and improve disk performance. PAV can either be static or dynamic. Dynamic PAV should be implemented when possible, since this provides more flexibility. z/OS Workload Manager (WLM) will manage the PAV devices as a group, instead of having a static relationship with the base device. In a static relationship the base device cannot borrow a PAV device from another base device that is not in use. In a dynamic environment, idle PAV devices are assigned to base devices that need more PAV devices to manage the workload. WLM manages the PAV devices on an LSS group level. Plan for the number of alias devices that your configuration will need.
8.6.5 I/O priority queuing (z/OS only)
I/O priority queuing allows the DS6000 series to use I/O priority information provided by the z/OS Workload Manager to manage the processing sequence of I/O operations. This enables the DS6000 to prioritize I/O workload if, for whatever reason, I/Os are queued in the DS6000.
8.6.6 Monitoring performance
A number of monitoring tools are available to measure the performance of your DS6000 once it is installed into your configuration.
For example, in the zSeries environment, the RMF™ RAID rank report can be used to investigate RAID rank saturation when the DS6000 is already installed in your environment. New counters will be reported by RMF to provide statistics on a volume level for channel and disk analysis.
In an open system environment the iostat command is useful to determine whether a system’s I/O load is balanced or whether a single volume is becoming a performance bottleneck. The tool reports I/O statistics for TTY devices, disks, and
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