HDD Printed circuit board (PCB) with board number 100579470 is usually used on these Seagate hard disk drives: ST32000641AS, 9WM, TK, PN 9GV168-301, FW CC13, Seagate 2TB SATA 3.5″ Hard Drive; ST31000524NS, 9WK, KRATSG, PN 9JW154-090, FW 1309, Seagate 1TB SATA 3.5″ Hard Drive; ST31000524NS, 9WK, KRATSG, PN 9JW154-075, FW AN11, Seagate 1TB SATA 3.5″…
HDD Printed circuit board (PCB) with board number 100687658 is usually used on these Seagate hard disk drives: ST1000DM003, Z1D, TK, PN 1CH162-501, FW CC44, Seagate 1TB SATA 3.5 Hard Drive; ST1000DM003, S1D, SU, PN 1CH162-302, FW CC46, Seagate 1TB SATA 3.5 Hard Drive; ST3000DM001, W1F, SU, PN 1CH166-302, FW CC26, Seagate 3TB SATA 3.5…
A
1394
The Institute of Electrical and Electronics Engineers (IEEE) designation for an interface developed for easy connection to consumer devices such as video and computer peripherals.
Adapter Card
In order to connect a computer to peripheral devices, an adapter card is often required. The adapter plugs into the computer’s bus, and connects the system’s data path to the peripheral.
Arrays
A group of disk drives that appear to a computer as a single logical unit. In order to use arrays effectively, RAID software and/or hardware is required.
B
Bandwidth
A data transmission rate; the maximum amount of information (bits/second) that can be transmitted along a channel.
Bus
A set of conductors connecting the various functional units in a system.
C
CD-R (Compact Disc-Recordable)
A blank CD that is designed to allow data to be “written” a single time on its surface. Peripheral devices that connect to PCs enable home or office single-time recording of blank CD-Rs.
CD-RW (Compact Disc-Rewritable)
A blank CD that is designed to allow data to be written, erased, and rewritten onto a CD-RW. Rewritable capability makes CDs more versatile by mimicking the usability of floppy disks.
D
Data Caching
Temporary storage of new write data or high-demand read data in solid-state memory in order to accelerate performance. The cached data is later overwritten with newly cached data once it is either written to disk or deemed to be of low demand.
Data Path
Digital information can be transmitted in different sized “paths” within a computer. Generally, the wider the data path, the higher the throughput performance. Today, the most standard data path width is 32-bit, though new products are entering the market with 64-bit paths, providing better I/O performance.
Disk Drive
Computer storage hardware that can read and write information on it.
E
EID
Enhanced Integrated Drive Electronics. A low cost, limited functionality drive interface. Controlled by the ANSI X3T9.2 committee.
Ethernet
A type of networking technology for local area networks.
F
Fault Tolerance
The ability of a system to continue to perform its functions, even when one or more components have failed.
Fibre Channel
A channel/network standard that provides connectivity, distance, and protocol multiplexing.
I
I/O Bus
The I/O bus is where the computer connects to outside peripherals.
I/O Channel
In computer systems, I/O Channel refers to the physical interface that controls the transfer of data between the computer and peripheral devices. With SCSI, each I/O Channel is equivalent to the full functionality of a single SCSI host adapter. For example, a dual-channel SCSI host adapter is equivalent to two single SCSI host adapters.
I/O Subsystem
The combination of technologies that manage the process of moving data into and out of the main computer system. The highest performance I/O subsystems use dedicated processors to minimize the CPU’s need to manage I/O, thereby allowing it to process the information that is moved to it from the I/O subsystem.
M
Mirroring
Also known as RAID 1 or duplexing (when using two host bus adapters). Full redundancy is obtained by duplicating all data from a primary disk on a secondary disk. The overhead of requiring 100% data duplication can get costly when using more than two drives.
Motherboard
The main printed circuit board in a system generally containing the bus, microprocessor, and chips used for controlling any internal peripherals.
Multitasking
The ability for the operating system to perform multiple operations at once. Windows NT Workstation is a multitasking operating system that can perform multiple I/O requests at once. SCSI and a Caching RAID coprocessor take advantage of multitasking.
N
Network Interface Card (NIC)
An adapter installed in a computer to provide a physical connection to a network.
P
Parity
When the data stream is split between several disks with an extra disk providing error protection.
PCI (Personal Computer Inter-connect)
PCI is the most common high-performance bus type. Currently, PCI uses a 32-bit wide data path, but newer PCI products are adopting a 64-bit wide data path for improved performance.
Peripheral
Internal or external devices connected by cable to a system.
R
RAID (Redundant Array of Independent/Inexpensive Disks)
A method of combining multiple disk drives into a single logical storage unit. Multiple levels of RAID provide different features. RAID Level 0 is the fastest type of RAID. It stores data across all the drives, letting users access information from multiple drives simultaneously. RAID Level 1 protects data by mirroring it on multiple drives, so performance is only slightly better than that of a single drive. RAID Level 5 does a combination of the two, providing the best overall balance.
Read-ahead Caching
A performance caching technique in which data is anticipated and read into the cache before it is actually requested.
S
SAN (Storage Area Network)
SANs are an evolving approach to storage, where multiple storage devices are connected to multiple servers for higher capacity, throughput, and reliability. SANs require sophisticated RAID management software and high-performance I/O connectivity.
SCSI (Small Computer System Interface, pronounced “scuzzy”)
SCSI is the preferred industry standard for high-performance I/O interface. Particularly valuable in servers where one system must connect to many high-capacity storage devices without lowering the I/O speed to the slowest device.
S.M.A.R.T. (Self-Monitoring Analysis and Reporting Technology)
Drives equipped with this feature report predicted failures based on threshold values determined by the manufacturer. This allows the network manager to replace a drive before it fails.
Storage
Computers store information on a variety of devices, some inside the system, and others external to the computer. Typically, data is written to a particular kind of storage medium using a disk drive. Common media include flexible (floppy disk drive), rigid (hard disk drive), tape, or optical (CD).
Striping
Also known as RAID 0. Two or more drives store and retrieve data in parallel, accelerating performance.
W
Write-back Caching
A performance caching technique in which the completion of a write request is signaled as soon as the data is in cache. Actual writing to the disk occurs at a later time.
Write-through Caching
A caching technique in which the completion of a write request is not signaled until data is safely stored on disk
Case:After the iPhone mobile phone data resumes the jailbreak, the data resumed Ms. Jiang sent her Apple iPhone4 to the mobile phone repair shop to upgrade. After the upgrade is completed, it is found that the still beloved photos have not been backup, and the request should be recovered as much as possible.Customers find the…
I use HD Tune to measure performance of the hard drive. The tests typically take 2-3 minutes and the transfer rate of a regular hard drive decreases dramatically as the test comes to a close. However, the SSD drive performance stays the same over (pic below) the life of the test. This happens on all…
DDE
Dynamic Data Exchange. A communication technique for Windows and OS/2. DDE Applications can send and receive data once a communication path is established.
Diffuse
To soften contrasting edges and fill areas of an image or object via random patterns. Also used to simulate colors outside the color pallet. see dithering
Digital
A system in which values are represented by a series of binary bits.
Digitizing
the process of encoding or converting images, sound, video and other data from analog or printed form to a digital format/specification. Examples: Scanning= Printed image to Digital Image file, video capture=analog video signal to still or motion digital file.
Dithering
The process of using patterns to simulate colors or gradients
DVI
digital video interactive. This is a compression format for recording digital video on a CD- ROM disk that provides up to 72 minutes of full motion video, or four hours of one-quarter screen full-motion video.
Case:Customers’ telephones describe that some folders of the computer can not be opened, and they often do crash.Engineers recommend that customers not to power on the hard disk, which will cause the bad disk bad sectors to spread, resulting in more file damage and more severe partition damage, which cannot be recognized to partitions. Solution:The…
Magnetic flux
The pattern of magnetic pole directions of the bits written on the disk.
Manufacturing Yield
The portion of unit production of a manufacturing process that is usable, saleable product; usually expressed as a percent of total output of that product.
Master
The first drive in a dual drive combination. A master drive by itself (with no slave) is called a single drive.
Media
In hard drives, the disks and their magnetic coatings; sometimes refers to the coating material alone.
MB (Megabyte)
Western Digital defines a megabyte as 1,000,000 (one million) bytes.
Mechanical Latencies
Include both seek time and rotational latency. Mechanical latencies are the main hindrance to higher performance in hard drives. The time delays of mechanical latencies are one hundred times higher than electronic (non-mechanical) latencies associated with the transferring of data. See also Seek Time, Rotational Latency.
Memory
A device or storage system capable of storing and retrieving data.
MFM (Multiple Frequency Modulation)
A method of encoding analog signals into magnetic pulses or bits.
MR Heads (Magneto-resistive Heads)
MR heads were developed to increase areal density and improve drive performance. MR heads use separate read and write elements, as opposed to traditional inductive thin-film read-write heads. MR heads use an inductive element for writing data, and a separate magneto-resistive element for reading information. The read element has a magnetically sensitive material that detects data recorded on the magnetic disk surface. MR head construction results in a stronger signal than that produced by inductive thin-film read-write heads, which permits it to read higher areal density data. Since the magneto-resistive element can only read data, a conventional thin-film inductive element writes data to the disk.
MTBF (Mean Time Between Failures)
Average time (expressed in hours) that a component works without failure. It is calculated by dividing the total number of operating hours observed by the total number of failures. Also, the length of time a user may reasonably expect a device or system to work before an incapacitating fault occurs.
MTTR (Mean Time to Repair)
The average time it takes to repair a drive in the field. In the field, only major subassemblies are changed (the PCB, sealed housing, etc.), excluding component level repairs as these are not performed in the field.
Multi-media
A simultaneous presentation of data in more than one form, such as by means of both visual and audio.
Multi-user
In information technology, a system that enables more than one user to access data at the same time.
Case:A factory array RAID5’s 3 300GB hard disks. Due to the sudden power off of the circuit failure server, the RAID information of the server was restarted to report an error. Solution:The engineer detects the hard disk hardware problem, then analyzes the array information and finds the correct array information. Finally, the virtual reorganization array…
Case:After the customer reinstalls the system by himself, the important data on the hard disk is backup, and the operating system is re -installed and re -installed. It was found that the backup was wrong. Solution:The data that the customer’s response must be recovered is some photos, which are stored in the D and E…
