Capacity design principles (1) : Physical capacity (for Mirroring)

The physical capacity of a drive consists of the valid physical capacity and the physical capacity of control information.

• Valid physical capacity [MiB] (totalRawCapacity): Capacity that becomes available as a result of adding the drive to a storage pool

• Physical capacity of control information [MiB] (metaDataPhysicalCapacity): The capacity for storing control information in the drive's total physical capacity allocated to the storage pool

For Mirroring, the valid physical capacity (C_rawDevice [MiB]) can be calculated by using the following expression:

The following formula is an approximate expression and there might be a margin of error of up to 1 GiB.

(CrawDevice[MiB]) = floor((Cdevice × 512/(512+8)) - 3072[MiB] - 99288[MiB], 99288[MiB])
    floor(value, reference value)
        : The value is rounded off to a multiple close to the reference
          value.
    Cdevice: Drive capacity[MiB]