Definition - What does RAID 5EE mean?
RAID 5EE is a type of nested RAID level that is similar to RAID level 5E but provides better spare drive features.
As with RAID level 5E, it further extends the capabilities of RAID level 5. The extended or additional spare drive is part of the overall RAID 5EE and can be used for input/output operations.
Techopedia explains RAID 5EE
Typically, RAID level 5EE integrates the hot spare within the stripe set rather than placing it at the end of the array, as in RAID level 5E. This enables faster rebuilding of drives if a drive fails. RAID level 5EE requires a minimum of four drives to operate and supports a maximum of 16 drives in an array. The hot spare drive space, which is empty by default, is used for copying data from a failed drive.