Dell Dual SD Flash Riser Card M420 blade server | CFWH0 X789H

The management riser card provides two card slots and offers the following features:
Internal Dual SD interface — maintains a mirrored configuration using SD cards in both slots (labeled as SD1 and vFlash/SD2) and provides redundancy

Single card operation — A single card in the SD1 card slot is supported, but does not offer redundancy. A vFlash card can be installed in the vFlash card slot on the blade chassis. The vFlash card provides persistent on-demand local storage and a custom deployment environment that allows automation of server configuration, scripts, and imaging.