Dell SRDF Introduction

Some restrictions and dependencies apply to SRDF/Metro configurations:

• Online Device Expansion (ODE) is available when both sides run PowerMaxOS 10 (6079) or PowerMaxOS 5978.444.444 and later.
• The R1 and R2 devices must be identical in size.
• In an SRDF/Metro group, all the R1 devices must be on one side of the SRDF link and all the R2 devices on the other side.
• Devices can have Geometry Compatibility Mode (GCM) set only if the configuration consists of arrays that run PowerMaxOS 5978 or later.
• Devices can have user Geometry set only if GCM is also set.
• Some operations apply to all devices in an SRDF/Metro group:
  • Setting devices Ready or Not Ready on the SRDF/Metro link. For example, there is no provision to apply an establish or suspend operation to a subset of devices in an SRDF/Metro group.
  • Changing bias.
• An SRDF/Metro configuration contains FBA or IBM i D910¹ devices only. It cannot contain CKD (mainframe) devices.
• Mobility IDs are allowed in SRDF/Metro configurations only when both sides run PowerMaxOS. If either side runs HYPERMAX OS, Mobility ID is not available. Also, both sides must use native IDs or Mobility IDs. An SRDF/Metro group cannot contain devices that use a mix of native IDs and Mobility IDs.

Interaction restrictions

Some restrictions apply to SRDF device pairs in an SRDF/Metro configuration with TimeFinder and Open Replicator (ORS):

• Open Replicator is not supported.
• Devices cannot be BCVs.
• Devices cannot be used as the target of a TimeFinder data copy when the SRDF devices are both:
  • RW on the SRDF link
  • In the SyncInProg, or active/active SRDF, or Active Bias pair state

Devices can, however, be used as the source of a TimeFinder data copy.