Case:Employees misunderstood and pulled out the hard disk, causing the array information to be lost. Solution:There are a small amount of bad disk No. 2 and 3 of the hard disk. First, the No. 2 and No. 3 hard disks are used for mirrors, and then the array information is analyzed, the virtual reorganization array…
Case:The customer is a car Co., Ltd., the unit’s laptop hard disk fails, manifested as the unable to recognize the hard disk by turning on. At the same time, the hard disk emits an abnormal sound. There are important data such as drawings and work documents.Essence Solution:1. Data recovery center engineers detected that the failure…
Half-Duplex
A communications protocol that permits transmission in both directions but in only one direction at a time.
Half-height Drives
Standard 3.5-inch hard drives are available in heights of 1.0-inch and 1.6-inches. Half-height drives measure 1.6-inches in height.
Hard Drive
An electromechanical device used for information storage and retrieval, incorporating one or more rotating disks on which data is recorded, stored and read magnetically. Western Digital’s principal product.
Hard Drive Industry
The combined manufacturers of hard drives. In the United States, the industry is led by IBM, Maxtor, Seagate, Quantum and Western Digital.
Hard Error
An error that is repeatable every time the same area on a disk is accessed.
Hard Sectored
A technique that uses a digital signal to indicate the beginning of a sector on a track.
Head
The minute electromagnetic coil and metal pole which write and read back magnetic patterns on the disk. Also known as a read/write head. A drive with several disk surfaces or platters will have a separate head for each data surface. See also MR Head.
Head Actuator
A motor that moves the head stack assembly in a hard drive to align read/write heads with magnetic tracks on the disks.
Head Crash
Refers to the damage incurred to a read/write head when the head comes into contact with the disk surface. A head crash might be caused by severe shock, dust, fingerprints, or smoke, and can cause damage to the surface of the disk and/or the head.
Head Disk Assembly (HDA)
The mechanical components of a hard drive, including the disks, heads, spindle motor and actuator.
Head Loading Zone
An area on the disk specifically reserved for the heads to use when taking off or landing when power to the drive is turned on or off. No data storage occurs in the head loading zone.
Head Stack Assembly
The electromechanical mechanism containing read/write heads and their supporting devices.
Headerless Format
The lack of a header or ID fields (track format). This enables greater format efficiency and increased user capacity.
High-end Market
The enterprise market.
High-Level Format
A high-level format must be performed (with EZ-Drive or the Format command) on your new Western Digital hard drive before you can use it. Formatting erases all the information on a hard drive and it sets up the file system needed for storing and retrieving files.
Host
The computer that other computers and peripherals connect to. See also initiator.
Host Adapter
A plug-in board that acts as the interface between a computer system bus and the disk drive.
Host Interface
The point at which the host and the drive are connected to each other.
Host Transfer Rate
Speed at which the host computer can transfer data across the SCSI interface; or, the speed at which the host computer can transfer data across the EIDE interface. Processor Input/Output (PIO) modes and Direct Memory Access (DMA) modes are defined in the ATA-4 industry specifications for the EIDE interface.
The Microsoft Windows operating system families (98SE,ME,2000,XP) do not support USB2 as a boot drive or primary system drive.
The Maxtor Personal Storage 160GB and above models are not supported as a boot drive for Macintosh operating systems because of Apple file system limitations. Some Macintosh platforms allow USB2 hard drives to function as the primary or boot drive. Check with Apple to see if your computer system supports booting to USB2 storage devices.
Microsoft® SQL server is a business enterprise software package that manages data through a client/server relational database. There are four fundamental aspects to a SQL (Structured Query Language) server.
1. Database File
2. Relational Database Concept
3. Client/Server System
4. Database Management System (DBMS)
The Database File refers to the physical file that contains the data the SQL server manages. This file is more than just a container for data. SQL files, or .MDF files, are highly organized and complex. The file is designed like this so that SQL server can handle multiple data transactions at once.
The Relational Database Concept is the method employed to organize the data; this is separate from the internal organization of the file itself. Relational Database Concept systems use mathematical set theory to organize the data in the most effective way. Data organization is critical to maintaining the speed of the database server.
The Client/Server System refers to the part of SQL server that communicates with the operating system. This part of the system needs to manage the server’s resources, connections and managing multiple databases at the same time.
The Database Management System interacts and works will all the above items. Not only does this manage the internal structure of the .MDF file, DBMS also controls the Relational Database side of things and organizes the data. The DBMS of SQL server is the heart of the system.
Data loss situations-What can happen?
Data loss situations can occur at a number of different levels. The first level of data loss starts with the storage device. This can be a single hard disk or a SAN or RAID storage array. The second level of data loss can start at a file system level. The file system is a unique method of storing and organizing system and user files. The operating system controls the file system. If the information about where data files are on the volume are damaged or lost, then adjustments or repairs need to be completed at a file system level. Once the file system is repaired then the file’s data stream can be accessed correctly. Most operating systems have a utility that will automatically fix the file system. These utilities work to make the volume accessible. However, this can permanently damage the data stream of the file. The third level of data loss can occur within the file itself. As previously mentioned, .MDF files are quite complex. The internal structure can be corrupted to the point where the DBMS will not make the database available.
The solution to data disasters
The process of a SQL recovery begins with finding the database file requested. If the database file is inaccessible due to problems with the storage device, then should work to get that data extracted. If the file is missing, deleted or truncated due to problems with the file system, then should work to adjust or repair the file system to correctly point to the data stream of the file. And finally if the file system has no pointers at all to the file, then should search the entire drive looking for SQL data.
The next stage is to work on the database file itself. This is where the SQL toolset comes. These tools analyze the complex internal structures of the .MDF file and provide reports as to what tables are recoverable. The reports also list the number of data rows that will come back.
Once the evaluation is complete and authorization is given to recover the data, the SQL toolset will copy the data into another SQL server database. After this phase is complete, we can backup or archive the recovered data.
Remote Data Recovery is the fastest solution for SQL recoveries. The Remote Data Recovery process will copy the recovered data into a SQL server that is setup on you or your client’s site. They only need SQL server running. For best results I recommend that the storage device we are working on be connected to a SQL server, because all of the data transactions will be occurring on a single machine.
Case:Customer Dell MD1000, a total of seven hard disks, 300G, raid5.Suddenly all the hard disks were bright yellow lights, and the server could not be accessed. Solution:The engineer of the data recovery center tested 7 hard disks and found that the No. 4 hard disk was severely damaged. The No. 3 hard disk had a…
This FAQ applies to all Seagate, Maxtor, Quantum ATA 66, ATA 100, and ATA 133 drives.
The faster timing requirements of Ultra ATA/66 and above require the use of an 80-conductor cable. This is necessary for proper operation of UDMA modes 3 and greater. The 80-conductor cable is used with the same connector configuration as the standard 40-conductor cable. The 40 additional conductors are used as ground paths and are all connected to the 7 original ground conductors. These additional ground conductors serve to improve the overall signal quality (signal-to-noise ratio) of the ATA cable. 80-conductor Ultra ATA cables are also limited to a maximum cable length of 18 inches.
If the drive was purchased in a retail kit and not as a “bare” drive, the kit includes an Ultra ATA cable as described here. If not Ultra ATA cables can be purchased from your system vendor or reseller and are fully backward compatible for operation on all standard/legacy ATA devices and hosts. However, these cables will typically utilize the cable select (CS) configuration on ATA drives for defining a master or slave device (drive 0 or drive 1). The drive placement convention used on an 80-conductor cable is also different from the previous generation of cable select type cables. The 80-conductor Ultra ATA cables require the master drive (drive 0) to be installed at the end of the cable and the slave drive (drive 1) to be installed on the middle connector.
The connectors on 80-conductor cables are also color-coded to help ensure proper drive placement and attachment to the host (system). Typical color-coding is as follows: blue for attachment to the host (system), black is for device 0 (master), and gray is for device 1 (slave).
HDD Printed circuit board (PCB) with board number 100627970 is usually used on these Seagate hard disk drives: The 100627970 Seagate PCB repair process can usually be divided into 2 steps: find a replacement PCB and firmware transfer. 100627970 Seagate PCB: Board Number Finding a donor Seagate PCB board is easy, you just need to…
Case:Customer 4G capacity SD cards took photos and videos of leadership activities of some units. When backup, the SD card accidentally burned and did not recognize on the computer.Looking for someone in the local area, it was stuck.But because it was encapsulated by BGA.Without Flash chips, local service providers said that they were unable to…
How can I navigate to a file or folder in NERDTree and change the working directory to that folder (or the folder containining the file I’m on). I know it’s possible to keep NERDTree in sync with the NERDTree root (nerdtree and current directory), but I’m looking for a macro or something that would change…
