During a FlashArray//X to FlashArray//XL hardware upgrade, when should the Implementation Engineer insert the DFMd...

Upgrading from a FlashArray//X to a FlashArray//XL involves a significant architectural change, often requiring a data migration or a specific "chassis replacement" workflow known as a Data-in-Place upgrade where the new chassis temporarily acts as an expansion shelf. In this specific procedure, the new FlashArray//XL chassis is not immediately populated with its final drives (DFMDs) before power-on because it first needs to be configured to accept data or join the cluster in a controlled state.

The procedure requires the Implementation Engineer to boot the FlashArray//XL chassis first and configure it into Shelf Mode (SPM) . Only after the chassis is successfully running in this mode—effectively acting as a passive SAS/Ethernet attached shelf to the existing controllers—are the DirectFlash Modules (DFMd) inserted.

Inserting them earlier could cause the array to attempt a full boot sequence or initialize a new array instance, complicating the upgrade logic. By waiting until Shelf Mode is confirmed, the engineer ensures that the modules are recognized correctly as part of the migration target resources, allowing Purity to manage the layout and data redistribution correctly from the source array.

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