Skip to main content
SANtricity 11.6
A newer release of this product is available.

Drive terminology


Learn how the drive terms apply to your storage array.

Component Description


Data Assurance (DA) is a feature that checks for and corrects errors that might occur as data is transferred through the controllers down to the drives. Data Assurance can be enabled at the pool or volume group level, with hosts using a DA-capable I/O interface such as Fibre Channel.

Drive Security feature

Drive Security is a storage array feature that provides an extra layer of security with either Full Disk Encryption (FDE) drives or Federal Information Processing Standard (FIPS) drives. When these drives are used with the Drive Security feature, they require a security key for access to their data. When the drives are physically removed from the array, they cannot operate until they are installed in another array, at which point, they will be in a Security Locked state until the correct security key is provided.

Drive shelf

A drive shelf, also called an expansion shelf, contains a set of drives and two input/output modules (IOMs). The IOMs contain SAS ports that connect a drive shelf to a controller shelf or to other drive shelves.


Deallocated or Unwritten Logical Block Error (DULBE) is an option on NVMe drives that allows a storage array to deallocate blocks that are part of a volume. Deallocating blocks on a drive can greatly reduce the time it takes to initialize volumes. In addition, hosts can deallocate logical blocks in the volume using the NVMe Dataset Management command.

FDE drives

Full Disk Encryption (FDE) drives perform encryption on the disk drive at the hardware level. The hard drive contains an ASIC chip that encrypts data during writes, and then decrypts data during reads.

FIPS drives

FIPS drives use Federal Information Processing Standards (FIPS) 140-2 level 2. They are essentially FDE drives that adhere to United States government standards for ensuring strong encryption algorithms and methods. FIPS drives have higher security standards than FDE drives.


Hard disk drives (HDDs) are data storage devices that use rotating metal platters with a magnetic coating.

Hot spare drives

Hot spares act as standby drives in RAID 1, RAID 5, or RAID 6 volume groups. They are fully functional drives that contain no data. If a drive fails in the volume group, the controller automatically reconstructs data from the failed drive to a hot spare.


Non-Volatile Memory Express (NVMe) is an interface designed for flash-based storage devices, such as SSD drives. NVMe reduces I/O overhead and includes performance improvements, as compared to previous logical-device interfaces.


Serial Attached SCSI (SAS) is a point-to-point serial protocol that links controllers directly to disk drives.

Secure-capable drives

Secure-capable drives can be either Full Disk Encryption (FDE) drives or Federal Information Processing Standard (FIPS) drives, which encrypt data during writes and decrypt data during reads. These drives are considered secure-capable because they can be used for additional security using the Drive Security feature. If the Drive Security feature is enabled for volume groups and pools used with these drives, the drives become secure-enabled.

Secure-enabled drives

Secure-enabled drives are used with the Drive Security feature. When you enable the Drive Security feature and then apply Drive Security to a pool or volume group on secure-capable drives, the drives become secure-enabled. Read and write access is available only through a controller that is configured with the correct security key. This added security prevents unauthorized access to the data on a drive that is physically removed from the storage array.


Solid-state disks (SSDs) are data storage devices that use solid state memory (flash) to store data persistently. SSDs emulate conventional hard drives, and are available with the same interfaces that hard drives use.