Glossary of Hard Disk Drive Terminology (Letter E)

ECC On-the-Fly
A hardware correction technique that corrects errors in the read buffer prior to host transfer without any performance penalties. These error corrections are invisible to the host system because they do not require assistance from the drive’s firmware.

EIDE (Enhanced Integrated Drive Electronics)
The primary interface used by desktop PCs to handle communication between hard drives and the central processing unit. The equivalent interface system in most enterprise systems is SCSI.

Embedded Servo Control
The embedded servo control design generates accurate feedback information to the head position servo system without requiring a full data surface (which is required with a “dedicated” servo control method) because servo control data is stored on every surface.

Encoding
The process of modifying data patterns prior to writing them on the disk surface.

Enterprise
The series of computers employed largely in high-volume and multi-user environments such as servers or networking applications; may include single-user workstations required in demanding design, engineering and audio/visual applications.

Enterprise Storage Group
The Western Digital operation that designs, produces and markets hard drives for the enterprise market.

Error Correction Code (ECC)
A mathematical algorithm that detects and corrects errors in a data field.

Error Log
A record that contains error information.

Error Rate
The number of errors of a given type that occur when reading a specified number of bits.

Extended Partition
You can create multiple partitions on a hard disk, one primary partition and one or more extended partition(s). Operating system files must reside on the primary partition. An extended partition is a partition where non-system files (files other than DOS or operating system files) can be stored on a disk. You can also create logical drives on the extended partition.