S ‐ Data Recovery Glossary
SAS– Serial Attached SCSI (SAS) is a computer bus technology designed primarily for
transfer of data to and from devices like CD‐ROM drives, hard drives, and so on.SAS
is a serial communication protocol for direct attached storage (DAS) devices. It is
designed as a replacement for the parallel SCSIin the corporate and enterprise
market, allowing for much higher speed data transfers than ever before, and is
backwards‐compatible with SATA drives. SAS uses serial communication instead of
the parallel method found in traditional SCSI devices, however, SCSI commands are
still utilized for interacting with SAS End devices.
SATA (Serial ATA) – First generation (1.5 Gbit/s) SATA ports on a motherboard. Serial
ATA) is a computer bus technology, in computer hardware, primarily designed for
transfer of data to and from optical drives and hard disks. It was designed as a
successor to the legacy Advanced Technology Attachment standard (ATA), and is
expected to eventually replace the older technology (retroactively renamed Parallel
ATA or PATA). Serial ATA adapters and devices communicate over a high‐speed serial
SCA‐2–Acronym for Single Connector Attach. It is an interface that incorporates a
blind mate connecter, grounding contact, hot swap capability, ESD protection, direct
plug misalignment tolerance and backplane connector options for SCSI devices. Also
called the 80‐pin SCSI connector.
SCSI–Acronym for Small Computer System Interface (pronounced skuh‐zee). It is a
collection of standards for transferring and physically connecting data between
peripheral devices and computers. It is commonly used for tape drives and hard disks
but it can also connect to a wide array of devices e.g. CD drives and scanners.
SCSI Configure Automatically (SCAM)– Allows users to attach SCSI devices without
worrying about configuration options.
SCSI‐1 – The Small Computer System Interface (ANSI document X3.131‐1986).
SCSI‐2 – The Small Computer System Interface (ANSI document X3.131‐1994).
SCSI‐3 – The ANSI X3T10 Working Documents (under development).
SCSI device – A host peripheral controller, computer adapter, or an intelligent
peripheral that can be attached to a SCSI bus.
SDRAM–Acronym for synchronous dynamic random Access memory (see also
DRAM). It incorporates new features that make it quicker than standard DRAM and
Sector– A 512‐byte packet of data in EIDE and SCSI hard drives. The smallest amount
of data can be written or read to the drive from the host interface. On UNIX and
Macintosh drives, sectors are grouped into blocks or logical blocks that are often
defined as a single sector. The terms block and sector are sometimes used
interchangeably according to the context. (Note: The meaning of the term block in
connection with the physical configuration of the disk is different from its meaning at
the system level. (See also block and cluster.)
Sector Slipping–A method utilized to push‐down defective sector sites when a
format or reassignment operation is taking place to retain sequential order of the
data. Spares are located throughout the disk for this purpose.
Seek – The movement of a set of read/write heads to a desired location. The
actuator transfers the heads to the cylinder containing the sector and track to where
the data is stored.
Seek Time – A measure (in milliseconds) of how fast the hard drive can move its
read/write heads to a specified location.
Self‐Monitoring, Analysis, and Reporting Technology (S.M.A.R.T.) – A technology to
help the user to prevent a possible system down time because of hard drive failure
by trying to predict imminent hard drive failure before it occurs.
Sequential Access – The writing or reading of data in a sequential order as opposed
to random access. Magnetic tape drives store data in sequential blocks.
Serial Storage Architecture (SAA)–The common name fixed to a set of standards
being developed by an ANSI‐approved X3 group. These set of standards defines a
new serial interface which provides a flexible addressing scheme.
Server – A computer used primarily to store data, providing access to shared
resources. Usually contains a network operating system.
Servo Burst – Provides positioning information to the actuator arm and is foundon
an entire surface (dedicated servo) or at equal intervals on eitherdisk surface
SharePoint Database – Collaborative portal application based on the Windows
SharePoint Services platform, a free component of Windows Server 2003. Windows
SharePoint Services offers online publishing of standard file formats.
Single‐ended SCSI–SCSI’s standard electrical interface.Single‐ended means an
interface withone corresponding ground line and one signal.For each SCSI signal.
Used primarily in applications requiring cable lengths under 19 feet (6 meters).
Slave – The second drive in a dual drive combination.
Slot–It is a physical connector to hold an expansion card on a motherboard, SIMM,
DIMM or a processor card in palace.
Socket – A receptacle usually on a motherboard, that processors or chips can be
Soft Error – An error that does not repeat when the same location is re‐read.
Soft Sectored – A technique that allows the controller to determine, by reading the
format information from the disk,
SPC – SCSI Primary Commands.
Spindle – The center, rod‐like axle on which the disks are mounted.
Spindle Motor – The motor that rotates the spindle and ultimately the disks.
Spindle Speed – See RPM.
Spindle Synchronization – A feature that causes SCSI hard drives in multiple‐drive
systems to rotate to the same address location at the same time.
Spreadsheet – The display of data in a form suitable for comparisons. Is used in
accounting and other applications. Also utilizes computer programs for these uses.
Storage Capacity – The amount of data that can be stored on a hard drive.
Sub‐1000 PC – The series of personal computers being designed for sale at prices at
or below $1,000 each.
Subsystem – A secondary or component part of a system, as a hard drive is a
subsystem of a personal computer.
Surface – The bottom or the top side of a platter coated with a magnetic material
needed to record data. A platter may use one or both surfaces to store data.
Synchronous Transmission – Transmission in which the receiving and sending
devices operate constantly at the same frequency and are held in a preferred phase
relationship by a correction device.
System Files – The files needed to run an operating system.
System Integrator – An independent professional who identifies and provides the
necessary combinations of hardware and software in response to an end user’s
System Registry – The system configuration files used by Windows 95, 98 and NT to
store settings about user preferences, installed software, hardware and drivers, and
other settings required for Windows to run correctly. The system updates the
registry every time you add new hardware or a new program to your system.
System Rescue Disk – See Boot Disk.
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