A systems administrator plans to use Non-Disruptive Migration (NDM) to migrate data (rom a VMAX array running Enginuity 5876 to a PowerMax running PowerMaxOS 5978 Which NDM mode is used?

Non-Disruptive Migration (NDM) establishes a temporary SRDF relationship between the source VMAX (Enginuity 5876) and the target PowerMax (PowerMaxOS 5978). During the copy phase NDM forces that SRDF link to run in Adaptive Copy Disk (ACD) mode so the entire source device is copied in the background without host impact and without the write-latency requirements of synchronous mode. Once the adaptive-copy transfer is complete, the pairs are briefly switched to synchronous for cut-over, but the NDM “mode” that characterises the migration process is Adaptive Copy.

A. Asynchronous – SRDF/A is not used by NDM; the link is set to Adaptive Copy Disk, not delta-set asynchronous.
C. Pass-through – “Pass-through” is a device state after cut-over, not the replication mode used for copying data.
D. Metro-based – NDM does not rely on SRDF/Metro or any metro-distance specific mode.

1. Dell EMC “Solutions Enabler SRDF Non-Disruptive Migration Technical Notes” (H17887)

Rev 02

2020: p.9

“NDM employs SRDF Adaptive Copy Disk mode to transfer data from the source array to the target array.”

2. Dell EMC “SRDF Product Guide for PowerMax and VMAX All Flash

” Rev 35

2019: Section 2.3.3

pp. 27-28

describes Adaptive Copy Disk and cites its use in NDM.

3. Dell EMC “PowerMaxOS 5978 SRDF for Open Replicator and NDM” courseware

Module 4

Slide 12: “NDM copy phase = SRDF ACD mode.”