2026-04-29

Glossary of Western Digital Hard Disk Drive (Letter N)

DATARECOVERYUNION.COM02 mins

NAS
Network attached storage. Hard disk storage that is set up with its own network address rather than being attached to the computer that is serving network workstation users.

NAT
Network Address Translation. Used in gateway devices that form the boundary between the public Internet and the private LAN. As IP packets from the private LAN traverse the gateway, NAT translates a private IP address and port number to a public IP address and port number, tracking those translations to keep individual sessions intact.

NCQ
Native command queuing. A command protocol implemented only on native SATA hard drives. It allows multiple commands to be outstanding within a drive at the same time. Drives that support NCQ have an internal queue where outstanding commands can be rescheduled and re-ordered dynamically, along with necessary tracking mechanisms for outstanding and completed parts of the workload. NCQ also has a mechanism that allows the host to issue additional commands to the drive while the drive is seeking data for another command.

NetCenter™
Trade name for WD’s first generation external network hard drive.

network computer
A computer with limited data storage capacity that communicates with a central data storage facility such as a server or RAID system.

NFS
NT file system. A file system, designed for Windows® NT, that supports long filenames, security access control, recovery, and other features.

NTFS
NT file system. A file system, designed for Windows® NT, that supports long filenames, security access control, recovery, and other features.

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SATA Drive Installation in Mac OS X

DATARECOVERYUNION.COM03 mins

hard drive install Installing a SATA Drive as a Storage Unit

  1. Physically install the drive into the Mac.
  2. Connect the drive to the motherboard or SATA add-on controller card.
  3. Connect the hard drive to the power source.
  4. Double-click on the Mac OS main hard drive on the Desktop.
  5. Select Applications.
  6. Select Utilities.
  7. Select Disk Utility.
  8. Select the Erase tab.
  9. Verify that the correct hard drive is illuminated in the left column.
  10. Select Mac OS Extended partition.
  11. Click Erase. (Note: This will erase all data from the drive.)
  12. Allow time for the drive to format.
  13. Verify the drive is mounted on the Desktop.

If this SATA drive will be the bootable drive and this is a new installation, you may follow the simplified steps:

  1. Physically install the drive into the Mac.
  2. Connect the drive to the motherboard or SATA add-on controller card.
  3. Connect the hard drive to the power source.
  4. Insert the Mac OS X install CD into the CD-ROM.
  5. Power on the computer while holding down the “C” key to boot from CD.
  6. Select Installer.
  7. Select Open Disk Utility.
  8. Highlight the drive.
  9. Select Erase.
  10. Choose Volume format of Mac OS Extended Partition.
  11. Click Erase. (Note: This will erase all data from the drive.)
  12. Click on Disk Utility and select Quit Disk Utility.
  13. Highlight Preferred Language and continue with the installation of the Mac OS operating system.

Note: If an error appears stating that the operating system cannot be installed on this volume, simply power down the Mac, connect the hard drive’s data cable to the other SATA port, and restart the process.

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bad sectors of samsung laptop

DATARECOVERYUNION.COM01 mins

Case:Mr. Li’s daughter opened a small company, and the company’s business information was stored on a computer, but the process of using the computer recently was particularly slow.Finally found that the information stored inside was gone Solution:After online inquiries, I found the data recovery center, and after the telephone consultation, I came to our company…

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Data recovery apparatus and method used for flash memory

DATARECOVERYUNION.COM08 mins

Flash data recovery1. A data recovery apparatus used for a flash memory that includes data areas and index areas in which values indicating whether data stored in the respective data areas are valid are recorded, comprising: a controller that performs a data operation at each of a plurality of logical addresses, and if the data operations performed at the plurality of logical addresses are successful, records a mark value in a last index area of a plurality of index areas respectively corresponding to the plurality of logical addresses.

2. The data recovery apparatus of claim 1, wherein the data operation is first performed on a middle portion of the flash memory and then on other portions of the flash memory, and the mark value is recorded in one of the index areas corresponding to the middle portion of the flash memory.

3. The data recovery apparatus of claim 1, wherein said plurality of logical addresses are consecutive logical addresses.

4. A data recovery apparatus used for a flash memory that includes data areas and index areas in which values indicating whether data stored in the respective data areas are valid are recorded, comprising: a controller that determines whether data respectively stored at a plurality of logical addresses prior to a predetermined logical address, through a data operation, are valid based on a mark value recorded in an index area corresponding to the predetermined logical address.

5. The data recovery apparatus of claim 4, wherein the mark value is recorded in index areas respectively corresponding to first and last logical addresses of the plurality of logical addresses when performing the data operation first on a middle portion of the flash memory and then on other portions of the flash memory, and determining whether data respectively stored at at least one of the plurality of logical addresses between the first and last logical addresses are valid based on the index areas in which the mark value is stored.

6. The data recovery apparatus of claim 5, wherein it is determined whether data stored at the predetermined logical address is valid based on whether data exists at a logical address subsequent to the predetermined logical address.

7. The data recovery method of claim 4, wherein said plurality of logical addresses are a plurality of consecutive logical addresses.

8. A data recovery method used for a flash memory that includes data areas and index areas in which values indicating whether data stored in the respective data areas are valid are recorded, the data recovery method comprising: performing a data operation at each of a plurality of logical addresses; and recording a mark value in a last index area of a plurality of index areas respectively corresponding to the plurality of logical addresses.

9. The data recovery method of claim 8, wherein, in the recording of the mark value, if the data operation is performed first on a middle portion of the flash memory and then on other portions of the flash memory, the mark value is recorded in an index area corresponding to the middle portion of the flash memory.

10. The data recovery method of claim 8, wherein said plurality of logical addresses are a plurality of consecutive logical addresses.

11. A data recovery method used for a flash memory that includes data areas and index areas in which values indicating whether data stored in the respective data areas are valid are recorded, the data recovery method comprising: identifying a mark value recorded in an index area corresponding to a predetermined logical address; and determining whether data respectively stored at a plurality of logical addresses prior to the predetermined logical address, through a data operation, are valid based on the mark value.

12. The data recovery method of claim 11, wherein in the determining operation, it is determined whether the data respectively stored at the plurality of logical addresses are valid based on a mark value recorded in an index area corresponding to one of the plurality of logical addresses where the data operation has performed most recently.

13. The data recovery method of claim 12, wherein, in the determining operation, if the data operation is performed first on a middle portion of the flash memory and then on other portions of the flash memory, it is determined whether data stored in the flash memory are valid based on the mark value recorded in the index area corresponding to the middle portion of the flash memory.

14. The data recovery method of claim 12, wherein it is determined whether data stored at a predetermined logical address is valid based on whether data exists at a logical address subsequent to the predetermined logical address.

15. The data recovery method of claim 13, wherein it is determined whether data stored at a predetermined logical address is valid based on whether data exists at a logical address subsequent to the predetermined logical address.

16. The data recovery method of claim 12, wherein said plurality of logical addresses are a plurality of consecutive logical addresses.

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