Dell PowerEdge RAID Controller 12 User’s Guide PERC H965i Adapter, PERC H965i Front, PERC H965i MX, and PERC H965e Adapter

Device enumeration

All devices attached to the controller are assigned an ID from a persistent range of numbers. This includes backplanes, physical disks, and virtual disks. When a backplane is discovered, it is assigned a range of IDs based on the number of slots the backplane has. Each slot is assigned a dedicated ID in ascending order from the reserved range. When a disk is inserted, an ID allocated to the slot will be assigned.

Virtual disks are assigned an ID based on creation. The first virtual disk created will be assigned ID 1 and increases for each virtual disk. If a virtual disk is deleted, a newly created virtual disk will reuse that ID before using the next free ID. The newly created virtual disk will only reuse that ID if more than 120 seconds have passed since the pervious virtual disk was deleted.

• Operating system device enumeration
  • All devices are presented to the operating system as a SCSI device.
  • Virtual disks and non-RAID disks are presented to the OS in the order of their ID.
    • virtual disks are presented first in ascending order of ID.
    • non-RAID disks are presented second in ascending order of physical disk ID.
  • In case of some automated OS installation processes, by default, the OS is installed on the disk that is first presented to the system. If you are installing to a virtual disk, it is recommended to make the first created VD the OS. If you installing to a non-RAID disk, it is recommended to install the disk in slot 0 of the front backplane.