How does VNX storage hard drive calculate the actual user available capacity?

Lenovo/emc vnx storage, after dividing the RAID, found that the available capacity and the actual disk configuration capacity does not match.

Solution:

1. The first four disks in the VNX series are system disks. The system occupies 300 GB of capacity for each of the first four disks. In the VNX2 generation storage, the system capacity accounts for GB;

2. For the sake of data security, VNX stores 520 bytes for each slice of the hard disk, not the traditional 512 bytes, which requires dividing by 1040 for capacity conversion, not 1024.

Available VNX1 storage hard disk capacity, refer to the following: