In computer
storage, SAF-TE (abbreviated from SCSI Accessed Fault-Tolerant Enclosure) is an industry standard to interface an
enclosure
Enclosure or Inclosure is a term, used in English landownership, that refers to the appropriation of "waste" or " common land" enclosing it and by doing so depriving commoners of their rights of access and privilege. Agreements to enclose land ...
in-band
In telecommunications, in-band signaling is the sending of control information within the same band or channel used for data such as voice or video. This is in contrast to out-of-band signaling which is sent over a different channel, or even o ...
to a (
parallel
Parallel is a geometric term of location which may refer to:
Computing
* Parallel algorithm
* Parallel computing
* Parallel metaheuristic
* Parallel (software), a UNIX utility for running programs in parallel
* Parallel Sysplex, a cluster of IBM ...
)
SCSI
Small Computer System Interface (SCSI, ) is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, electrical, optical and logical interface ...
subsystem in order to gain access to information or control for various elements and parameters. These include temperature, fan status, slot status (populated/empty), door status, power supplies, alarms, and indicators (e.g.
LEDs
A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (cor ...
,
LCDs).
[SAF-TE IR ''1.0 Introduction''] Practically, any given SAF-TE device will only support a subset of all possible sensors or controls.
[SAF-TE IR ''3.0 SAF-TE Interface'']
Scope
![SCSI-SCA-backplane](https://upload.wikimedia.org/wikipedia/commons/f/f6/SCSI-SCA-backplane.jpg)
Many
RAID
Raid, RAID or Raids may refer to:
Attack
* Raid (military), a sudden attack behind the enemy's lines without the intention of holding ground
* Corporate raid, a type of hostile takeover in business
* Panty raid, a prankish raid by male college ...
controllers can utilize a SAF-TE "activated"
backplane
A backplane (or "backplane system") is a group of electrical connectors in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus. It is used as a backbo ...
by detecting a swapped drive (after a defect) and automatically starting a rebuild. A passive subsystem usually requires a manual rescan and rebuild.
A SAF-TE device (SEP) is represented as a
SCSI processor device that is polled every few seconds by e.g. the RAID controller software.
Due to the low overhead required, impact on bus performance is negligible.
[SAF-TE IR ''2.0 SCSI Specification''] For
SAS or
Fibre Channel
Fibre Channel (FC) is a high-speed data transfer protocol providing in-order, lossless delivery of raw block data. Fibre Channel is primarily used to connect computer data storage to servers in storage area networks (SAN) in commercial data cen ...
systems, SAF-TE is replaced by the more standardized
SCSI Enclosure Services
SCSI Enclosure Services (SES) is a protocol for more modern SCSI enclosure products. An initiator can communicate with the enclosure using a specialized set of SCSI commands to access power, cooling, and other non-data characteristics.
SES device ...
(SES).
The most widely used version was defined in the SAF-TE Interface Specification Intermediate Review R041497, released on April 14, 1997 by
nStor (now part of
Seagate Technology
Seagate Technology Holdings plc is an American data storage company. It was incorporated in 1978 as Shugart Technology and commenced business in 1979. Since 2010, the company has been incorporated in Dublin, Ireland, with operational headquart ...
) and
Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...
.
Command interface
Status requests are performed as ''READ BUFFER''
SCSI command
In SCSI computer storage, computers and storage devices use a client-server model of communication. The computer is a client which requests the storage device to perform a service, e.g., to read or write data. The SCSI command architecture was or ...
s, enclosure action requests as ''WRITE BUFFER'' commands.
See also
*
International Blinking Pattern Interpretation The International Blinking Pattern Interpretation (IBPI) is an internal computer hardware standard.
It defines two items:
# How SGPIO is interpreted into states for drives or slots on a backplane.
# How light emitting diodes (LEDs) on a backplane s ...
(IBPI)
*
Out-of-band signaling
In telecommunication, signaling is the use of signals for controlling communications. This may constitute an information exchange concerning the establishment and control of a telecommunication circuit and the management of the network.
Classif ...
*
SGPIO
Serial general purpose input/output (SGPIO) is a four-signal (or four-wire) bus used between a host bus adapter (HBA) and a backplane. Of the four signals, three are driven by the HBA and one by the backplane. Typically, the HBA is a storage con ...
(Serial General Purpose Input/Output)
*
SCSI Enclosure Services
SCSI Enclosure Services (SES) is a protocol for more modern SCSI enclosure products. An initiator can communicate with the enclosure using a specialized set of SCSI commands to access power, cooling, and other non-data characteristics.
SES device ...
(SES)
*
*
hw.sensors
The hw.sensors framework is a kernel-level hardware sensors framework originating from OpenBSD, which uses the sysctl kernel interface as the transport layer between the kernel and the userland. , the framework is used by over a hundred devi ...
References
External links
*
SAF-TE as part of Intel's IPMISAF-TE Intermediate Review R041497*
Computer data storage
Computer hardware standards
SCSI
System administration
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