The disks in an array are usually configured into smaller sets named RAID groups which provide protection against failure.
The RAID groups define the manner in which the group of physical disks handle data when it is written to the disks within that group. The main aim is that data to be protected.
For this reason, you must create logical unit numbers (LUNs) correctly.
This article describes all the steps that will help you to create LUNs after RAID failure.