Definition - What does RAID 6E mean?
RAID 6E is a type of RAID 6 configuration that has an integrated hot spare drive.
The E in RAID 6E stands for "extended" as it adds on or extends the capabilities of standard RAID 6. It is part of the overall RAID operations and can be used for input/output operations.
Techopedia explains RAID 6E
The addition of a hot spare drive enables increased performance and reduction of input/output operations per drive, as it is used in all I/O processes. The spare drive can only be used per array, not with other RAID arrays.
The hot spare is a logical instance of the drive, not a physical instance. This spare drive is spread across disks, utilizing 10% of the space on each disk. Each spare block/drive is located at the end of the array.