NF5280M5 Backplane YZBB-00617-101: Slot Numbers Start at 2
Source configuration
An NF5280M5 shipped with the 25-port YZBB-00617-101 backplane, identified as BB_Inspur_NF5270M5_SAS12G_2.5x25_slot2, reports controller slots starting at 2 rather than 0:
The source explains that this encoding was intended for a configuration with a rear backplane, but some early systems without that rear backplane also used it. It says later shipments without a rear backplane should use YZBB-00617-102 for controller numbering starting at 0. This is an archived configuration/part-selection note, not proof of universal interchangeability or a recommendation to replace an installed backplane solely to renumber disks.
Use physical DISK labels for the stated service case
For the source’s 617-101 configuration, the BMC SEL DISK number matches the chassis’s printed disk-label overlay. Its relation to the controller slot is:
DISK number = RAID slot number - 2
DISK19 = RAID slot21 - 2The source fault example identifies DISK19:
The physical label diagram identifies bay 19 in red; bay 17 is also highlighted in yellow in the original and is retained without being relabeled as the failed drive:
Controller-derived views use the slot number
The pictured controller-derived storage view shows Slot 21, Drive 28, SAS HDD, 1117.31 GB, FAILED. Drive 28 is a controller device identifier and is not the physical DISK number. For this configuration, replace the physical bay labelled 19 after confirming the current machine and drive identity, rather than pulling a bay labelled 21 because the controller says slot 21.
The last diagram retains the controller slot grid 2–26, red 21 and yellow 19, plus the separate row labelled Front with 0, 1, 27. Do not apply the minus 2 rule to arbitrary backplanes or configurations. Correlate SEL, chassis labels and the exact platform’s supported service/locate procedure before physical replacement.