PC-3000 for SCSI

PC-3000 for SCSIPC-3000 for SCSI is a first-to-market professional hardware-software solution for testing, diagnosing the failures and recovering data from Hard Disk Drives with SCSI and SAS interfaces in tandem with Data Extractor SCSI.

  • SAS (Serial Attached SCSI) are supported.
  • SCSI-2, Ultra SCSI, Ultra2 SCSI, Ultra 160 SCSI, Ultra 320 SCSI is supported.
  • Original user-friendly interface similar to that one of PC-3000 for Windows.
  • PC-3000 for SCSI can work with 1 up to 15 Hard Disk Drives simultaneously; make tests and service operations for each of them and independently from all the other drives.
  • New PC-KEY2 (Power supplier) card can control power supply of one HDD.
  • Three external power sources of ATX standard, you can connect several HDDs to each of them. DBMS for resource storage – one of the most safe database of all existing ones.
  • PC-3000 for SCSI hardware-software product can function under these Operating systems: Microsoft Windows 98/ME, Windows 2000, Windows XP. Requirements to your PC hardware are determined by the requirements to the OS. SCSI adapter must be installed.
  • Know-how manuals with different methodologies of data recovery, recommendations on interchangeability of PCBs, succession of making hot-swap.

More about PC-3000 please refer to this post: Hard Drive Repair Tool PC3000 System

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SCSI Hard Drive Failures

SCSI Hard Drive FailuresSCSI stands for Small Computer System Interface. It is the second-most popular hard disk interface used in PCs today. Many companies use SCSI hard drives because the interface allows for much faster data transfer speeds. One of the main differences with a SCSI hard drive and an ATA hard drive is a SCSI disk must have an independent controller for it to communicate with the operating system.

Although SCSI controller has many benefits, it still adds another layer, another chance for failure and data loss. Unlike the IDE counterparts, SCSI disks operate through their own SCSI BIOS. When the computer is powered up, the SCSI BIOS sends a “Start Unit Request” command to the SCSI devices under its control. If the drive fails to start correctly, the SCSI drive will (often) power down and the error “Start Unit Request Failed” is displayed.

Which caused the SCSI drive failure?
Power down / power up
: SCSI drives are often found in machines that “never” switch off. When eventually these machines are powered down, getting the SCSI drives to restart can often be difficult

Electronic Failure: Failure of the electronic circuitry on the hard disk will prevent the drive from starting, fortunately drives with this type of failure are often recoverable

Mechanical Failure: Often characterized by a clucking sound or high pitched whine, SCSI hard disk mechanical failures are often the worst type of failure these drives can suffer. The noises, though not always apparent, are indicative of an internal mechanical failure or head crash.

All the usual failures that can be found on hard disk drives e.g. bad sectors, logical corruption etc.

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SCSI Levels

SCSI Levels SCSI – Small Computer System Interface

An intelligent peripheral interface characterized by its use of high level communication between devices. Communications are defined as being between an “Initiator” and a “Target”. The Initiator is normally a computer, and the Target is normally a peripheral. Data may be transferred in asynchronous (not clocked) or synchronous (clocked) mode. All messages and commands are always transferred in asynchronous mode.

This term is often used to describe the published ANSI standard now called SCSI-1 (X3.131-1986).

SCSI-2

This is a term describing the published ANSI standard (X3.131-1994). SCSI-2 was an upgrade from the original SCSI interface. Changes included faster data rates and mandated message and command structure to improve compatibility. Synchronous data transfer rate for SCSI-2 is 2.5 to 10 Mbytes/sec for an 8-bit data bus (N/ND models), and 5.0 to 20 Mbytes/sec for a 16-bit data bus (W/WC/WD/DC models).

SCSI-3

This term describes a set of related ANSI standards that are currently being developed for the SCSI bus. The SCSI-2 document is very large (400+ pages) and covers the full range of topics. SCSI-3 split this large document into a series of smaller documents, each covering a “layer” of the interface definition.

The basic layers are:

physical (connectors, pin assignments, electrical specifications)

protocol (physical layer activity is organized into bus phases, packets, etc.)

architecture (a description of how command requests are organized, queued, and responded to by any protocol)

primary commands (description of commands that must be supported by all SCSI devices)

device specific commands (commands that are specific to a particular class of devices; CD-ROMs or -WORM drives, for example)

The set of standards needed to do a SCSI-3 parallel interface disc drive implementation are:

SPI (SCSI Parallel Interface) for the physical layer
SIP (SCSI Interlocked Protocol) for the protocol layer
SAM (SCSI Architecture Model) for the architecture
SPC (SCSI Primary Commands) for the primary command set
SBC (SCSI Block Commands) for the disc drive specific command set
The SCSI-3 standards are layered in this manner to allow substitution of parts of the structure as new technology emerges. For example, a comparable set of standards for a SCSI Fiber Channel interface disc drive replaces the physical and protocol layers with new documents but uses the same documents for the other 3 layers. The main point to remember here is that the terms SCSI-2 or SCSI-3 do not imply any particular performance per se, rather they refer to the generation of documents to which a product conforms. Since the newest features are only in SCSI-3 and tend to be higher performing, SCSI-3 devices should demonstrate better performance than SCSI-2 in most cases.

SCSI FAST

This refers to timings defined in SCSI-2 for a 10 MegaTransfer/sec transfer rate. A “MegaTransfer” (MT) is a unit of measure referring to the rate of signals on the interface regardless of the width of the bus. For example, a 10 MT/sec rate on a 1 byte wide (narrow) bus results in a 10 Mbytes/sec transfer rate, but on a 2 byte (wide) bus, it results in a 20 Mbytes/sec transfer rate.

SCSI FAST-20

This refers to timings defined in SCSI-3 SPI for a 20 MT/sec transfer rate, which achieves data rates twice as fast as SCSI FAST rates. For example, a 20 MT/sec rate on a 1 byte wide (narrow) bus results in a 20 Mbytes/sec transfer rate, but on a 2 byte (wide) bus, it results in a 40 Mbytes/sec transfer rate.

SCSI FAST-40

This refers to timings being defined for a future revision of the SCSI-3 SPI that achieve 40 MT/sec, which is twice as fast as SCSI FAST-20 rates. For example, a 40 MT/sec rate on a 1 byte wide (narrow) bus results in a 40 Mbytes/sec transfer rate, but on a 2 byte (wide) bus, it results in an 80 Mbytes/sec transfer rate. For more information, see Ultra2 SCSI.

SCSI FAST-80

This refers to timings being defined for a future revision of the SCSI-3 SPI that achieve 80 MT/sec, which is twice as fast as SCSI FAST-40 rates. For example, an 80 MT/sec rate on a 1 byte wide (narrow) bus results in an 80 Mbytes/sec transfer rate, but on a 2 byte (wide) bus, it results in a 160 Mbytes/sec transfer rate.

Ultra SCSI

This is a term describing the latest published ANSI standard (X3T10/1071D rev. 6), commonly known as Fast-20. Ultra SCSI, like all synchronous transfers, is a negotiated clock rate. For more information, see The UltraSCSI Buzz.

Ultra2 SCSI

This is a term describing the latest published ANSI standard (X3T10/1071D rev. 6), commonly known as Fast-40. Ultra2 SCSI, like all synchronous transfers, is a negotiated clock rate.

SCSI Narrow

This term refers to the 1 byte wide data bus on a 50-pin parallel interface that is defined in the ANSI standard SCSI-1 (X3.131-1986).  The narrow bus consists of 8 data lines with parity, a series of control lines and the matching ground lines.  Seagate designates a narrow SCSI interface with an “n” in the model number.

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SCSI WIDE

This term usually refers to the 2 byte wide data bus on a 68 pin parallel interface that is defined in the SCSI-3 SPI document. The term can be generically applied to any implementation wider than 1 byte, but at the time of this writing, there are no implementations wider than 2 bytes. Future implementations may include more data bytes because FAST transfer rates are giving plenty of life to 2 byte transfers until serial interfaces (like Fibre Channel or FireWire) become more popular. Seagate designates a wide SCSI interface with a “w” in the model number.

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SCSI FAST-WIDE

This refers to a combination of a FAST transfer rate with a 2 byte wide connector, resulting in an increased data transfer rate. Wide FAST-20 (40 Mbytes/sec) products will be available in the year of this writing. Wide FAST-40 (80 Mbytes/sec) and FAST-80 (160 Mbytes/sec) products will be available in the near future.

Differential or High Voltage Differential (HVD)

Differential (D, ND, WD, WDC) is a logic signal system used in some SCSI drives. It uses a paired plus and minus signal level to reduce the effects of noise on the SCSI bus. Any noise injected into the signal would be present in both a plus and minus state, thereby being canceled. Seagate designates a differential (high voltage) SCSI interface with a “d” in the model number.

Due to changing definitions, Differential is now often referred to as High Voltage Differential (HVD).

Low Voltage Differential (LVD)

Low Voltage Differential is a differential logic scheme using lower voltage levels than HVD. For more information, see Ultra2 SCSI. Seagate designates low voltage differential SCSI interface with an “l” in the model number.

Fibre Channel Arbitrated Loop (FCAL)

This is the formal name for the Fibre Channel system used by SCSI. It is more commonly known as Fibre Channel SCSI. The loop part of the name refers to the way the system is connected as one large ring. Because of the loop characteristics, this interface has more in common with local area networks than with parallel SCSI.

Fibre Channel SCSI

This refers to products with fibre channel physical and protocol layers using the SCSI command set. The Fibre Channel interface is completely different from parallel SCSI in that it is a serial interface, meaning command and data information is transmitted on one signal stream organized into packets. The fibre may be either a copper coaxial cable or a fiber optic cable. The signal on the first implementation of fibre channel uses a 1 GHz rate, thereby achieving 100 Mbytes/sec over the cable. Fibre channel also implements increased software control of configuration and pushes the total device count on the bus to 126 IDs, as opposed to only 8 or 16 on a parallel bus. For more information, see our Technology Paper on Fibre Channel. Seagate designates a fiber channel SCSI interface with an “fc” in the model number.

ASA-2 SCSI

This is a Seagate specific term describing the basic structure of the SCSI firmware included with a Seagate disc drive and standing for Advanced SCSI Architecture, generation 2. It provides better performance than ASA-1 code in certain user environments (such as sequential 1 block data transfers). The labels ASA-1 and ASA-2 can apply to code shipped on a wide range of products, meaning different products have firmware originating from the same base firmware, but such firmware is individually adapted to the particular servo and read/write channel hardware on that product. The performance of a disc drive is still primarily determined by the seek times and data transfer rates, but the code base label provides a level of commonality and lack of bugs assurance in SCSI features for all drives with that label.

The most attractive feature of a common code architecture is that most enhancements made on one drive (such as a Barracuda 4) can be quickly migrated to other drives (such as the Barracuda 2 or Hawk 4) developed from the same code base. All new products since January 1995 use the ASA-2 code base, and many older products developed with ASA-1 code have been updated to the new structure.

SCA-2

This is a miniature D style, 80 pin connector used on SCSI drives to plug to backplane connections. The SCA-2 connector provides grounds, voltage, and control lines needed to allow hot-plugging of parallel interface SCSI drives. Seagate designates an SCA-2 SCSI interface with a “c” in the model number.

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CD Optical Storage Glossary of Computer Terms (Letter S)

Scanning
The most common practice of encoding real images into digital form Accomplished by use of a scanner which passes an image sensor across the original

Screen grabs
Common term for the capturing screen rasterization images and video stills to digital files. Can be preformed with software or hardware, but quality may vary between method used.

SCSI
Small Computer System Interface. The abbreviation is pronounced “scuzzy.” A connection that allows high-speed information transfer between the computer and any external devices at speeds in the range of 4 to 5 megabytes per second. This specification also allows multiple devices to be connected via addresses to a single port (receptacle).

SCSI-II
A specification developed to provide greater speed and performance. An SCSI-II connection provides transfer rates ranging from 10 to 40 megabytes per second.

Selection

The term for indicating the desired area to be effected by editing.

Sharpen
To increase contrast along object edges to improve image appearance.

SIMM
Single In-line Memory Module. A small narrow circuit board containing Random Access Memory Chips (the electronic devices that store data while your computer works with it). SIMMs plug into special slots inside the computer to give the computer extra memory.

Special effects
Digital image manipulation techniques for enhancing quality or creating unusual appearances. Can also be used to remove undesirable image attributes.

Spray
To paint with a diffused edge to simulate “air-brush” feathering

Storyboard
A method of planning the content of a presentation by drawing sketches of each screen with notes about what happens in that scene.

Substitution
the process of replacing colors in a image with colors or patterns on the pallet for the image. this is implemented during color format conversion and pallet correction

SyQuest
A manufacturer of SCSI removable cartridge hard drives. This drive specification has been widely used in pre-press and publishing situations.

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RAID Array & Server Glossary of Computer Terms (Letter S)

SCSI
Small computer system interface (pronounced scuzzy). The fast, intelligent input/output parallel bus used by high-performance peripherals.

Software-based array
An array in which all management functions including parity calculation (XOR) are performed by the host server CPU. These products are low priced but have high CPU utilization and limited fault-tolerant features. High-performance, low-cost array adapters are quickly replacing these inferior software-based arrays.

System disk
The disk (or array) on which a system’s operating system is stored and from which it is initially loaded into system memory.

SAF-TE
SCSI Accessed Fault-Tolerant Enclosure, an “open” specification designed to provide a comprehensive standardized method to monitor and report status information on the condition of disk drives, power supplies, and cooling systems used in high availability LAN servers and storage subsystems. The specification is independent of hardware I/O cabling, operating systems, server platforms, and RAID implementation because the enclosure itself is treated as simply another device on the SCSI bus. Many other leading server, storage, and RAID controller manufacturers worldwide have endorsed the SAF-TE specification. Products compliant with the SAF-TE specification will reduce the cost of managing storage enclosures, making it easier for a LAN administrator to obtain base-level fault-tolerant alert notification and status information. All Mylex RAID controllers feature SAF-TE.

Sector
The unit in which data is physically stored and protected against errors on a fixed-block architecture disk.

Segment Size
See Cache Line Size

Sequential I/O
A type of read and write operation where entire blocks of data are accessed one after another in sequence, as opposed to randomly.

SES
SCSI Enclosure Services, a standard for SCSI access to services within an enclosure containing one or more SCSI devices. For disk drives, power supplies, cooling elements, and temperature sensors, the actions performed are the same as for SAF-TE monitoring. If a UPS is connected to any SES-monitored enclosures, and an AC failure or two minute warning is reported, conservative cache is enabled and all system drives are switched to write-through cache. Primarily used in fibre enclosures.

Session
The period of time between any two consecutive system shutdowns; system shutdown may be either a power off/on, or a hardware reset.

SMART
Self-Monitoring Analysis and Reporting Technology, the industry standard reliability prediction indicator for both the ATA/IDE (advanced technology attachment/integrated drive electronics) and SCSI hard disk drives. Hard disk drives with SMART offer early warning of some hard disk failures so critical data can be protected.

Spanning
A process that provides the ability to configure multiple drive packs or parts of multiple drive packs. In effect, spanning allows the volume used for data processing to be larger than a single drive. Spanning increases I/O speeds, however, the probability of drive failure increases as more drives are added to a drive pack. Spanned drive packs use striping for data processing. See also Striping and Drive Groups, Drive Packs.

Standard Disk Drive
This term refers to a hard disk drive with SCSI, IDE, or other interface, attached to the host system through a standard disk controller.

Standby Replacement of Disks
See also Hot Spare. One of the most important features the RAID controller provides to achieve automatic, non-stop service with a high degree of fault-tolerance. The controller automatically carries out the rebuild operation when a SCSI disk drive fails and both of the following conditions are true:

  • A “standby” SCSI disk drive of identical size is found attached to the same controller;
  • All of the system drives that are dependent on the failed disk are redundant system drives, e.g., RAID 1, RAID 3, RAID 5, and RAID 0+1.

Note: The standby rebuild will only happen on the same DAC960 controller, never across DAC960 controllers.

During the automatic rebuild process, system activity continues as normal. System performance may degrade slightly during the rebuild process.

To use the standby rebuild feature, you should always maintain a standby SCSI disk in your system. When a disk fails, the standby disk will automatically replace the failed drive and the data will be rebuilt. The system administrator can disconnect and remove the bad disk and replace it with a new disk. The administrator can then make this new disk a standby.

The standby replacement table has a limit of 8 automatic replacements in any session (from power-on/reset to the next power-off/reset). When the limit of 8 is reached and a disk failure occurs, the standby replacement will occur but will not be recorded in the replacement table.

To clear the “standby replacement” table, reboot the system from a DOS bootable floppy, run the configuration utility and select the option ‘view/update configuration’ from the main menu. A red box labeled ‘Drive Remap List’ will be displayed. Selecting the box will allow you to continue. You should save the configuration without making any changes, and exit the configuration utility. This will clear the replacement table. You may now proceed to boot your system and continue normal operations.

In normal use, the replacement table limit of 8 should not cause any problems. Assuming that a disk fails about once a year (drives we support generally come with a 5-year warranty), the system would run continuously for a minimum of 8 years before the table would need to be cleared.

Storage Device
A collective term for disks, tape transports, and other mechanisms capable of non-volatile data storage.

Stripe Order
The order in which SCSI disk drives appear within a drive group. This order must be maintained, and is critical to the controller’s ability to “rebuild” failed drives.

Stripe Size
The size, in kilobytes (1024 bytes) of a single I/O operation. A stripe of data (data residing in actual physical disk sectors, which are logically ordered first to last) is divided over all disks in the drive group.

Stripe Width
The number of striped SCSI drives within a drive group.

Striping
The storing of a sequential block of incoming data across multiple SCSI drives in a group. For example, if there are 3 SCSI drives in a group, the data will be separated into blocks. Block 1 of the data will be stored on SCSI drive 1, block 2 on SCSI drive 2, block 3 on SCSI drive 3, block 4 on SCSI drive 1, block 5 on SCSI drive 2, and so on. This storage method increases the disk system throughput by ensuring a balanced load among all drives.

Sub-System Storage
A collection of disks providing data storage space to a system user.

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