Monthly Archives: February 2015

JFET

Electronic engineering – Electronic devices and circuits

Electronic devices: Energy bands in silicon, intrinsic and extrinsic silicon. Carrier transport in silicon: diffusion current, drift current, mobility, resistivity. Generation and recombination of carriers. p-n junction diode, Zener diode, tunnel diode, BJT, JFET, MOS capacitor, MOSFET, LED, p-i-n and avalanche photo diode, LASERs. Device technology: integrated circuit fabrication process, oxidation, diffusion, ion implantation, photolithography, n-tub, p-tub and twin-tub CMOS process.

Electronic engineering – Electronic devices and circuits

Analog circuits: Equivalent circuits (large and small-signal) of diodes, BJTs, JFETs, and MOSFETs

MOSFET – Circuit symbols

Electronic component – Transistors

JFET (Junction Field-Effect Transistor) – N-CHANNEL or P-CHANNEL

Electronic component – Optoelectronic devices

Opto-Isolator, Opto-Coupler, Photo-Coupler – Photodiode, BJT, JFET, SCR, TRIAC, Zero-crossing TRIAC, Open collector IC, CMOS IC, Solid state relay (SSR)

Semiconductor device – Transistor

The field may be applied by a reverse-biased p–n junction, forming a junction field-effect transistor (JFET) or by an electrode isolated from the bulk material by an oxide layer, forming a metal–oxide–semiconductor field-effect transistor (MOSFET).

Transistor

Structure: BJT, JFET, IGFET (MOSFET), insulated-gate bipolar transistor, “other types”

Transistor

Functionally, this makes the n-channel JFET the solid-state equivalent of the vacuum tube triode which, similarly, forms a diode between its grid and cathode

Transistor

Metal–semiconductor FETs (MESFETs) are JFETs in which the reverse biased p–n junction is replaced by a metal–semiconductor junction. These, and the HEMTs (high-electron-mobility transistors, or HFETs), in which a two-dimensional electron gas with very high carrier mobility is used for charge transport, are especially suitable for use at very high frequencies (microwave frequencies; several GHz).

Transistor

Unlike bipolar transistors, FETs do not inherently amplify a photocurrent. Nevertheless, there are ways to use them, especially JFETs, as light-sensitive devices, by exploiting the photocurrents in channel–gate or channel–body junctions.

Transistor

Nearly all JFETs are depletion-mode because the diode junctions would forward bias and conduct if they were enhancement-mode devices; most IGFETs are enhancement-mode types.

Transistor

JFET, where the gate is insulated by a reverse-biased p–n junction

Transistor

MESFET, similar to JFET with a Schottky junction instead of a p–n junction

JFET

The junction gate field-effect transistor (JFET or JUGFET) is the simplest type of field-effect transistor. It can be used as an electronically-controlled switch or as a voltage-controlled resistance. Electric charge flows through a semiconducting channel between “source” and “drain” terminals. By applying a reverse bias voltage to a “gate” terminal, the channel is “pinched”, so that the electric current is impeded or switched off completely.

JFET – Structure

The JFET is a long channel of semiconductor material, doped to contain an abundance of positive charge carriers or holes (p-type), or of negative carriers or electrons (n-type). Ohmic contacts at each end form the source (S) and drain (D). A pn-junction is formed on one or both sides of the channel, or surrounding it, using a region with doping opposite to that of the channel, and biased using an ohmic gate contact (G).

JFET – Function

JFET operation is like that of a garden hose. The flow of water through a hose can be controlled by squeezing it to reduce the cross section; the flow of electric charge through a JFET is controlled by constricting the current-carrying channel. The current also depends on the electric field between source and drain (analogous to the difference in pressure on either end of the hose).

JFET – Function

Some JFET devices are symmetrical with respect to the source and drain.

JFET – Schematic symbols

The JFET gate is sometimes drawn in the middle of the channel (instead of at the drain or source electrode as in these examples). This symmetry suggests that “drain” and “source” are interchangeable, so the symbol should be used only for those JFETs where they are indeed interchangeable.

JFET – Comparison with other transistors

At room temperature, JFET gate current (the reverse leakage of the gate-to-channel junction) is comparable to that of a MOSFET (which has insulating oxide between gate and channel), but much less than the base current of a bipolar junction transistor. The JFET has higher transconductance than the MOSFET, as well as lower flicker noise, and is therefore used in some low-noise, high input-impedance op-amps.

JFET – History of the JFET

The first practical JFETs were made many years later, in spite of their conception long before the junction transistor

JFET – Mathematical model

The current in N-JFET due to a small voltage VDS is given by:

Diode – Types of semiconductor diode

These are actually JFETs with the gate shorted to the source, and function like a two-terminal current-limiter analog to the Zener diode, which is limiting voltage. They allow a current through them to rise to a certain value, and then level off at a specific value. Also called CLDs, constant-current diodes, diode-connected transistors, or current-regulating diodes.

Electronic symbol – Reference designations

JFET: Junction gate field-effect transistor

Electronic symbol – Transistors

n-channel junction gate field-effect transistor (JFET)

Electronic symbol – Transistors

p-channel junction gate field-effect transistor (JFET)

Field-effect transistor – History,

The field-effect transistor was first patented by Julius Edgar Lilienfeld in 1926 and by Oskar Heil in 1934, but practical semiconducting devices (the JFET) were developed only much later after the transistor effect was observed and explained by the team of William Shockley at Bell Labs in 1947. The MOSFET, which largely superseded the JFET and had a more profound effect on electronic development, was invented by Dawon Kahng and Martin Atalla in 1960.

Field-effect transistor – Types of field-effect transistors

The JFET (junction field-effect transistor) uses a reverse biased p–n junction to separate the gate from the body.

Field-effect transistor – Types of field-effect transistors

The MESFET (metal–semiconductor field-effect transistor) substitutes the p–n junction of the JFET with a Schottky barrier; and is used in GaAs and other III-V semiconductor materials.

Silicon carbide – Power electronic devices

In 2008, the first commercial JFETs rated at 1200 V were introduced to the market, followed in 2011 by the first commercial MOSFETs rated at 1200 V

MOSFET – Circuit symbols

Comparison of enhancement-mode and depletion-mode MOSFET symbols, along with JFET symbols (drawn with source and drain ordered such that higher voltages appear higher on the page than lower voltages):[http://www.circuitstoday.com/electronic-circuit-symbols Electronic Circuit Symbols]IEEE 315[http://highered.mcgraw-hill.com/sites/dl/free/0073191639/366537/Chapter_4.pdf#page=19 Microelectronic Circuit Design], Jaeger, Blalock – Figure

Schottky barrier – Devices

A MESFET, or metal–semiconductor field effect transistor|FET uses a reverse biased Schottky barrier to provide a depletion region that pinches off a conducting channel buried inside the semiconductor (similar to the JFET where instead a p–n junction provides the depletion region). A variant of this device is the high-electron-mobility transistor (HEMT), which also utilizes a heterojunction to provide a device with extremely high conductance.

Triode – Operation

The triode is very similar in operation to the n-channel JFET; it is normally on, and progressively switched off as the grid/gate is pulled increasingly negative of the source/cathode.

Threshold voltage

The threshold voltage of a JFET|junction field-effect transistor is often called ‘pinch-off voltage’ instead, which is somewhat confusing since pinch off for an MOSFET|insulated-gate field-effect transistor is used to refer to the channel length modulation|channel pinching that leads to current saturation behaviour under high source–drain bias, even though the current is never off. The term threshold voltage is unambiguous and refers to the same concept in any field-effect transistor.

Vacuum tube – Description

The solid-state device which operates most like the pentode tube is the junction field-effect transistor (JFET), although vacuum tubes typically operate at over a hundred volts, unlike most semiconductors in most applications.

Electronic component – Transistors

**JFET (Junction Field-Effect Transistor) – N-CHANNEL or P-CHANNEL

Electronic component – Optoelectronic devices

** Opto-isolator|Opto-Isolator, Opto-Coupler, Photo-Coupler – Photodiode, BJT, JFET, SCR, TRIAC, Zero-crossing TRIAC, Open collector IC, CMOS IC, Solid state relay (SSR)

Constant current diode

‘Constant-current diode’ (also called ‘CLD’, ‘current-limiting diode’, ‘diode-connected transistor’ or ‘CRD’, ‘current-regulating diode’) consists of a JFET with the gate shorted to the source, and it functions like a two-terminal current limiter or current source (analogous to a voltage-limiting Zener diode)

SPICE – Device models

SPICE2 included many semiconductor device transistor models|compact models: three levels of MOSFET model, a combined Ebers-Moll model|Ebers–Moll and Gummel–Poon model|Gummel-Poon bipolar model, a JFET model, and a model for a diode|junction diode. In addition, it had many other elements: resistors, capacitors, inductors (including Inductance#Coupled inductors|coupling), independent voltage source|voltage and current sources, ideal transmission lines, and voltage and current controlled sources.

Education and training of electrical and electronics engineers – Electronic devices and circuits

‘Electronic Devices’: Energy bands in silicon, intrinsic and extrinsic silicon. Carrier transport in silicon: diffusion current, drift current, mobility, resistivity. Generation and recombination of carriers. p-n junction diode, Zener diode, tunnel diode, BJT, JFET, MOS capacitor, MOSFET, LED, p-I-n and avalanche photo diode, LASERs. Device technology: integrated circuits fabrication process, oxidation, diffusion, ion implantation, photolithography, n-tub, p-tub and twin-tub CMOS process.

Education and training of electrical and electronics engineers – Electronic devices and circuits

‘Analog Circuits’: Equivalent circuits (large and small-signal) of diodes, BJTs, JFETs, and MOSFETs

Electronics engineering – Electronic devices and circuits

p-n junction diode, Zener diode, tunnel diode, BJT, JFET, MOS capacitor, MOSFET, LED, p-i-n diode|p-i-n and avalanche photo-diode|avalanche photo diode, LASERs

Regenerative circuit – Advantages and disadvantages

Intrinsically, there is little or no difference in the gain and stability available from vacuum tubes, JFET’s, MOSFET’s or bipolar junction transistors (BJT’s).

Channel (transistors) – Types of field-effect transistors

* The ‘JFET’ (junction field-effect transistor) uses a reverse biased p–n junction to separate the gate from the body.

Channel (transistors) – Types of field-effect transistors

* The ‘MESFET’ (metal–semiconductor field-effect transistor) substitutes the p–n junction of the JFET with a Schottky barrier; and is used in GaAs and other III-V semiconductor materials.

Quite Universal Circuit Simulator – Components

There is also a Component library that includes various standard components available in the market (bridges, diodes, varistors, LEDs, JFETs, MOSFETS, and so on).

Overclocking – Cooling

Moreover, silicon-based junction gate field-effect transistors (JFET) will degrade below temperatures of roughly and eventually cease to function or freeze out at since the silicon ceases to be semiconducting so using extremely cold coolants may cause devices to fail.

Hartley oscillator – Operation

The most simple of implementations shown here uses nothing but a Junction FET|JFET (in Common-drain configuration) and the LC tank circuit (here the single winding is tapped), plus a single battery; it will work, but probably with high distortion and high current drain (that could be improved by adding resistance between the source and the coil tap), and serves as an uncomplicated illustration of the Hartley oscillator operation:

Hartley oscillator – Operation

* the output from the JFET’s source (emitter, if a Bipolar Junction Transistor|BJT had been used; cathode for a triode) has the same phase as the signal at its gate (or base) – and roughly the same voltage as its input (which is the voltage across the entire tank circuit), but the current is amplified, i.e. it is acting as a Buffer amplifier#Current buffer|current buffer or VCVS|voltage-controlled voltage-source.

P-type semiconductor – Use of extrinsic semiconductors

Field-effect transistors (FET) are another type of transistor implementing extrinsic semiconductors. As opposed to BJTs, they are unipolar and considered either N-channel or P-channel. FETs are broken into two families, JFET|junction gate FET (JFET) and insulated gate FET (MOSFET|IGFET).

Metal oxide semiconductor field effect transistor – Circuit symbols

Comparison of enhancement-mode and depletion-mode MOSFET symbols, along with JFET symbols

Gilbert cell – Function

A functionally equivalent circuit may be constructed using field-effect transistors (JFET, MOSFET) or Thermionic valve|vacuum tubes.

Low-noise amplifier

For low noise, the amplifier needs to have a high amplification in its first stage. Therefore Junction Field-Effect Transistor|JFETs and High Electron Mobility Transistor|HEMTs are often used. They are driven in a high-current regime, which is not energy-efficient, but reduces the relative amount of shot noise. Input and output Impedance matching|matching circuits for narrow-band circuits enhance the gain (see Gain-bandwidth product).

Ngspice – Status of Ngspice simulator

Ngspice implements various circuits elements, like resistors, capacitors, inductors (single or mutual), transmission lines and a growing number of semiconductor devices like diodes, bipolar transistors, mosfets (both bulk and SOI), mesfets, jfet and HFET.

Transistors – Field-effect transistor (FET)

Metal–semiconductor FETs (MESFETs) are JFETs in which the Reverse-biased|reverse biased p–n junction is replaced by a metal–semiconductor junction. These, and the HEMTs (high-electron-mobility transistors, or HFETs), in which a two-dimensional electron gas with very high carrier mobility is used for charge transport, are especially suitable for use at very high frequencies (microwave frequencies; several GHz).

Transistors – Field-effect transistor (FET)

Nearly all JFETs are depletion-mode because the diode junctions would forward bias and conduct if they were enhancement-mode devices;

Transistors – Other transistor types

**JFET, where the gate is insulated by a reverse-biased p–n junction

Transistors – Other transistor types

**MESFET, similar to JFET with a Schottky junction instead of a p–n junction

List of computing and IT abbreviations – J

* JFET—Junction Field-Effect Transistor

AESA – Basic concept

The introduction of JFETs and MESFETs did the same to the transmitter side of the systems as well

Current source – Current-stable nonlinear implementation

A JFET can be made to act as a current source by tying its gate to its source. The current then flowing is the IDSS of the FET. These can be purchased with this connection already made and in this case the devices are called constant current diode|current regulator diodes or constant current diodes or current limiting diodes (CLD).

Current source – Constant current diode

The simplest constant-current source or sink is formed from one component: a JFET with its gate attached to its source. Once the drain-source voltage reaches a certain minimum value, the JFET enters saturation where current is approximately constant. This configuration is known as a constant-current diode, as it behaves much like a dual to the constant voltage diode (Zener diode) used in simple voltage sources.

Current source – Constant current diode

Due to the large variability in saturation current of JFETs, it is common to also include a source resistor (shown in the image to the right) which allows the current to be tuned down to a desired value.

MESFET

MESFETs are usually constructed in compound semiconductor technologies lacking high quality surface passivation such as gallium arsenide|GaAs, indium phosphide|InP, or Silicon carbide|SiC, and are faster but more expensive than silicon-based JFETs or MOSFETs

List of ISO 639-3 language codes reserved for local use – qa–

Nikon D2H

The ‘Nikon D2H’ is a professional-grade digital single-lens reflex camera introduced by Nikon Corporation on July 22, 2003. It uses Nikon’s own JFET-LBCAST sensor with a 4.1 megapixel resolution, and is optimised for sports and action shooting that require a high frame rate. In 2005, the D2H was replaced by the D2Hs, which added new features derived from the 12 megapixel Nikon D2X|D2X digital SLR. The D2Hs was discontinued after the introduction of the Nikon D300|D300 and Nikon D3|D3 models.

Flicker noise

Flicker noise is often characterized by the corner frequency fc between the region dominated by the low-frequency flicker noise and the higher frequency flat-band noise. MOSFETs have a higher fc (can be in the GHz range) than JFETs or bipolar transistors, which is usually below 2 kHz for the latter.

Power semiconductor device – Wide band-gap semiconductors

A SiC Schottky diode with a breakdown voltage of 1200V is commercially available, as is a 1200V JFET

Tube sound – Tube sound from transistor amplifiers

In 1982, Tom Scholz, a graduate of MIT and a member of Boston (band)|Boston, introduced the Rockman (music)|Rockman, which used JFET/BJT-based operational amplifiers and diode-based clipping circuits, but achieved a distorted sound adopted by many well known musicians. Advanced digital signal processing offers the possibility to simulate tube sound. Algorithms are currently available that transform digital sound from a CD or other digital source into a distorted digital sound signal.

Trigate transistors – Flexfet

‘Flexfet’ is a planar, independently double-gated transistor with a Copper interconnect|damascene metal top gate MOSFET and an implanted JFET bottom gate that are self-aligned in a gate trench

Discrete transistor – Types

* Structure: Bipolar junction transistor|BJT, JFET, IGFET (MOSFET), insulated-gate bipolar transistor, other types

Discrete transistor – Other transistor types

** JFET, where the gate is insulated by a reverse-biased p–n junction

Discrete transistor – Other transistor types

** MESFET, similar to JFET with a Schottky junction instead of a p–n junction

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25 Reports That Have Been Extensive For JDBC

February 28, 2015Newsposter

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JDBC

ODBC – ODBC-to-JDBC (or simply ODBC-JDBC) bridges

An ODBC-JDBC bridge consists of an ‘ODBC’ driver which uses the services of a JDBC driver#Type 1 Driver – JDBC-ODBC bridge|JDBC driver to connect to a database. This driver translates ODBC function-calls into JDBC method-calls. Programmers usually use such a bridge when they lack an ODBC driver for a particular database but have access to a JDBC driver.

ODBC – JDBC-to-ODBC (or simply JDBC-ODBC) bridges

independent data-access vendors deliver JDBC-ODBC bridges which support current standards for both mechanisms, and which far outperform the JVM built-in.

JDBC

‘JDBC’ is a Java-based data access technology (Java Standard Edition platform) from Oracle Corporation. This technology is an Application programming interface|API for the Java (programming language)|Java programming language that defines how a client may access a database. It provides methods for querying and updating data in a database. JDBC is oriented towards relational databases. A JDBC-to-ODBC bridge enables connections to any ODBC-accessible data source in the JVM host environment.

Datasource – Sun’s DataSource Overview [http://java.sun.com/j2se/1.4.2/docs/guide/jdbc/getstart/datasource.html]

A driver vendor will provide a class that is a basic implementation of the DataSource interface as part of its Java Database Connectivity (JDBC) 2.0 or 3.0 driver product

JDBC driver

A ‘JDBC driver’ is a software component enabling a Java (programming language)|Java application to interact with a database.[ java.sun.com/javase/technologies/database/ Java SE Technologies – Database] JDBC drivers are analogous to ODBC drivers, ADO.NET data providers, and OLE DB providers.

JDBC driver

To connect with individual databases, Java Database Connectivity|JDBC (the Java Database Connectivity Application programming interface|API) requires drivers for each database. The JDBC driver gives out the Database Connection|connection to the database and implements the Protocol (computing)|protocol for transferring the query and result between Client (computing)|client and database.

JDBC driver

JDBC technology drivers fit into one of four categories.[ www.oracle.com/technetwork/java/overview-141217.html Sun JDBC Overview]

JDBC driver – Type 1 Driver – JDBC-ODBC bridge

The JDBC type 1 driver, also known as the ‘JDBC-ODBC bridge’, is a database driver implementation that employs the ODBC driver to connect to the database. The driver converts JDBC method calls into ODBC function calls.

JDBC driver – Type 1 Driver – JDBC-ODBC bridge

Sun provides a JDBC-ODBC Bridge driver: sun.jdbc.odbc.JdbcOdbcDriver. This driver is native code and not Java, and is closed source.

JDBC driver – Type 1 Driver – JDBC-ODBC bridge

It may sometimes be the case that more than one JDBC driver is capable of connecting to a given URL. For example, when connecting to a given remote database, it might be possible to use a JDBC-ODBC bridge driver, a JDBC-to-generic-network-protocol driver, or a driver supplied by the database vendor. In such cases, the order in which the drivers are tested is significant because the DriverManager will use the first driver it finds that can successfully connect to the given URL.

JDBC driver – Type 1 Driver – JDBC-ODBC bridge

First the DriverManager tries to use each driver in the order it was registered. (The drivers listed in jdbc.drivers are always registered first.) It will skip any drivers that are untrusted code unless they have been loaded from the same source as the code that is trying to open the connection.

JDBC driver – Disadvantages

*Performance overhead since the calls have to go through the jdbc Overhead bridge to the ODBC driver, then to the native db connectivity interface (thus may be slower than other types of drivers).

JDBC driver – Type 2 Driver – Native-API Driver

The JDBC type 2 driver, also known as the ‘Native-API driver’, is a database driver implementation that uses the client-side libraries of the database. The driver converts JDBC method calls into native calls of the database API.For example: Oracle OCI driver is a Type 2 Driver

JDBC driver – Type 3 Driver – Network-Protocol Driver(MiddleWare Driver)

The JDBC type 3 driver, also known as the Pure Java Driver for Database ‘Middleware’, is a database driver implementation which makes use of a middle tier between the calling program and the database. The middle-tier (application server) converts JDBC calls directly or indirectly into the vendor-specific database protocol.

JDBC driver – Functions

*Sends JDBC API calls to a middle-tier net server that translates the calls into the DBMS-specific network protocol. The translated calls are then sent to a particular DBMS.

JDBC driver – Functions

*The JDBC Client driver written in java, communicates with a middleware-net-server using a database independent protocol, and then this net server translates this request into database commands for that database.

JDBC driver – Type 4 Driver – Database-Protocol Driver(Pure Java Driver)

The JDBC type 4 driver, also known as the Direct to Database ‘Pure Java Driver’, is a database driver implementation that converts JDBC calls directly into a vendor-specific database protocol.

JDBC driver – Type 4 Driver – Database-Protocol Driver(Pure Java Driver)

As the database protocol is vendor specific, the JDBC client requires separate drivers, usually vendor supplied, to connect to different types of databases. This type includes, for example, the widely used Oracle database|Oracle thin driver.

JDBC driver – List of JDBC Drivers

* [http://devapp.sun.com/product/jdbc/drivers List of drivers registered with Oracle]

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Thirty-Three Blueprints That All JBOD Controllers Know To Be Genuine

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JBOD

Logical Volume Manager (Linux) – Common uses

Creating single logical volumes of multiple physical volumes or entire hard disks (somewhat similar to RAID 0, but more similar to JBOD), allowing for dynamic volume resizing.

Non-standard RAID levels – BeyondRAID

It has the advantage of supporting multiple disk sizes at once, much like JBOD, while providing redundancy for all disks and allowing a hot-swap upgrade at any time

Vinum volume manager

Vinum, is a logical volume manager, also called Software RAID, allowing implementations of the RAID-0, RAID-1 and RAID-5 models, both individually and in combination. Vinum is part of the base distribution of the FreeBSD operating system. Versions exist for NetBSD, OpenBSD and DragonFly BSD. Vinum source code is currently maintained in the FreeBSD source tree. Vinum supports raid levels 0, 1, 5, and JBOD. Vinum is invoked as gvinum (GEOM Vinum) on FreeBSD version 5.4 and up.

Windows 2000 – Basic and dynamic disk storage

* ‘Spanned volumes’, where up to 32 disks show up as one, increasing it in size but not enhancing performance. When one disk fails, the array is destroyed. Some data may be recoverable. This corresponds to JBOD#Concatenation (JBOD or SPAN)|JBOD and not to Redundant array of independent disks#RAID 1|RAID-1.

Synology Inc. – Company Milestones

** DSM 2.1 is released. New features: GUI update, RAID-5+Spare support, JBOD Support, and storage scalability.

Logical Volume Manager (Linux) – Common uses

* Creating single logical volumes of multiple physical volumes or entire hard disks (somewhat similar to RAID 0, but more similar to JBOD), allowing for dynamic volume resizing.

Windows Server 2003 – Features

* ‘JBOD systems’: JBOD (Just a bunch of discs) systems, by using VDS, can manage a group of individual storage devices as a single unit. There is no need for the storage units to be of the same maker and model.

Sun Modular Datacenter – History

In late 2003, employees of the Internet Archive wrote a paper proposing an outdoor petabyte JBOD Network-attached storage|NAS box of sufficient capacity to store the then-current Archive in a 40′ shipping container. The first implementation of the concept have been realized using Sun Microsystems’ Modular Datacenters in March 2009.

Gluster – Architecture

The GlusterFS architecture aggregates compute, storage, and I/O resources into a global namespace. Each server plus attached commodity storage (configured as direct-attached storage, JBOD, or using a storage area network) is considered to be a node. Capacity is scaled by adding additional nodes or adding additional storage to each node. Performance is increased by deploying storage among more nodes. High availability is achieved by replicating data n-way between nodes.

ZFS – ZFS and hardware RAID

Therefore the recommendation is to not use a hardware RAID card, or to flash a hardware RAID card into JBOD/IT mode

ZFS – ZFS and hardware RAID

When using hardware RAID, the controller usually adds controller-dependent data to the drives which prevents software RAID from accessing the user data. While it is possible to read the data with a compatible hardware RAID controller, this inconveniences consumers as a compatible controller usually isn’t readily available. Using the JBOD/RAID-Z combination, any disk controller can be used to resume operation after a controller failure.

ZFS – ZFS and hardware RAID

Note that hardware RAID configured as JBOD may still detach disks that do not respond in time (like green hard drives), and as such, may require Time-Limited Error Recovery|TLER/CCTL/ERC-enabled disks to prevent drive dropouts.

Windows Home Server – Drive Extender

* Arbitrary storage expansion by supporting any type of hard disk drive (Serial ATA, Universal Serial Bus|USB, FireWire etc.) in any mixture and capacity mdash; similar in concept to Non-RAID drive architectures#JBOD|JBOD

Massive array of idle disks

* ‘JBOD’ (derived from ‘just a bunch of disks’): an architecture involving multiple hard drives, while making them accessible either as independent hard drives, or as a combined (spanned) single logical volume with no actual RAID functionality.

Massive array of idle disks

* ‘SPAN’ or ‘BIG’: A method of combining the free space on multiple hard drives to create a spanned volume. Such a concatenation is sometimes also called JBOD. A SPAN or BIG is generally a spanned volume only, as it often contains mismatched types and sizes of hard drives.

Massive array of idle disks – JBOD

‘JBOD’ (abbreviated from ‘just a bunch of disks’) is an architecture using multiple hard drives, but not in a RAID configuration, thus providing neither redundancy nor performance improvements. Hard drives may be handled independently as separate logical volumes, or they may be combined into a single logical volume using a volume manager like Logical Volume Manager (Linux)|LVM; such volumes are usually called spanned.

Massive array of idle disks – JBOD

When combined into a single logical volume, JBOD configurations are also called linear, as separate hard drives are concatenated in a linear manner to form a logical volume. Due to its nature, no redundancy is provided with this configuration, meaning that failure of a single hard drive destroys the logical volume as a whole. Linux software RAID (md), in addition to LVM, supports creation of such non-RAID linear volumes.

RAID1 – Non-standard RAID levels and non-RAID drive architectures

Alternatives to the above designs include nested RAID levels, non-standard RAID levels, and non-RAID drive architectures. Non-RAID drive architectures are referred to by similar acronyms, notably non-RAID drive architectures#SLED|SLED, JBOD|Just a Bunch of Disks, Spanned volume|SPAN/BIG, and Massive array of idle disks|MAID.

OpenMediaVault – Features

* RAID#Software-RAID|Software-RAID with the RAID#Standard levels|RAID-Level 0, 1, 4, 5, 6 and 10 plus JBOD

Digital cinematography – File-based workflows

Such RAID arrays, both of managed (for example, Storage Area Network|SANs and Network Attached Storage|NASs) and unmanaged (for example, Just a Bunch of Disks|JBoDs on a single computer workstation), are necessary due to the enormous throughput required for real-time (320 MB/s for 2K @ 24fps) or near-real-time playback in post-production, compared to throughput available from a single, yet fast, hard disk drive

Linux MD RAID 10 – BeyondRAID

It has the advantage of supporting multiple disk sizes at once, much like JBOD, while providing redundancy for all disks and allowing a hot-swap upgrade at any time

List of Thunderbolt-compatible devices – Hard Drive and SSD solutions

*[http://www.datoptic.com/ec/jbod-raid-data-storage-solutions/thunderbolt.html Desktop and rackmount Thunderbolt options with or without drives]

Spanned volume

Spanned volumes are a non-RAID drive architecture, and may be implemented in hardware or software; they may be referred to as Concatenation, SPAN, BIG, or JBOD, though this latter is ambiguous – JBOD may also refer to each physical disk being presented as a separate logical volume.

Dual-channel architecture – Ganged versus unganged

On the other hand, with JBOD (which equals to unganged mode) it is relied on the statistical usage patterns to ensure increased overall performance through even usage of all available hardware units.

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The Best J2SE Guide You Will Ever Read

February 28, 2015Newsposter

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J2SE

Java version history – J2SE 1.2 (December 8, 1998)

This and subsequent releases through J2SE 5.0 were rebranded retrospectively ‘Java 2’ and the version name J2SE (Java Platform, Standard Edition|Java 2 Platform, Standard Edition) replaced JDK to distinguish the base platform from J2EE (Java Platform, Enterprise Edition|Java 2 Platform, Enterprise Edition) and J2ME (Java Platform, Micro Edition|Java 2 Platform, Micro Edition)

Java version history – J2SE 1.3 (May 8, 2000)

The most notable changes were:[http://web.archive.org/web/20070817053430/http://www.sun.com/smi/Press/sunflash/2000-05/sunflash.20000508.3.xml Version 1.3 press release], Sun.[http://java.sun.com/j2se/1.3/docs/relnotes/features.html Version 1.3 full list of changes], Sun.

Java version history – J2SE 1.3 (May 8, 2000)

* HotSpot JVM included (the HotSpot JVM was first released in April 1999 for the J2SE 1.2 JVM)

Java version history – J2SE 1.4 (February 6, 2002)

This was the first release of the Java platform developed under the Java Community Process as [http://www.jcp.org/en/jsr/detail?id=59 JSR 59]. Major changes included:[http://web.archive.org/web/20070815095726/http://www.sun.com/smi/Press/sunflash/2002-02/sunflash.20020206.5.xml Version 1.4 press release].[http://java.sun.com/j2se/1.4.2/docs/relnotes/features.html Version full 1.4 list of changes].

Java version history – J2SE 1.4 (February 6, 2002)

* Java Web Start included (Java Web Start was first released in March 2001 for J2SE 1.3) (Specified in [http://www.jcp.org/en/jsr/detail?id=56 JSR 56].)