IBM Midrange System DS4000 Series Hardware Manual page 189

Setting the controller clocks
Because the DS5000 storage subsystem stores its own event log, you need to synchronize
the controller clocks with all the host systems accessing it. This improves problem
determination procedures. If you have not already set the clocks on the storage subsystems,
set them now. Be sure that your local system is using the correct time, and then select
Storage Subsystem  Set Controller Clock (Figure 4-34).
Figure 4-34 Setting the controller clock
Setting a security password
For security reasons, especially if the DS5000 storage subsystem is directly attached to the
network, you should set a password. This password is required for all actions on the DS5000
storage subsystem that change or update the configuration in any way.
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Chapter 4. IBM System Storage DS planning and configuration