Glossary of Western Digital Hard Disk Drive (Letter F)

FAT
Western Digital Hard Disk Drive File allocation table. A data table stored at the beginning of each partition on a disk and used by the operating system to determine which sectors are allocated to each file and in which sequence.

FAT32
A file allocation table system with a maximum file transfer of 4 GB and a maximum partition size of 32 GB.

FC
Fibre channel. The general name given to an integrated set of standards being developed by an ANSI-approved X3 group. This set of standards defines new protocols for flexible information transfer. Fibre channel supports three topologies: point-to-point, arbitrated loop, and fabric.

FC-AL
Fibre channel-arbitrated loop. A serial storage interface designed for high-end applications. A subset of FC network systems interconnection.

FDB
Fluid dynamic bearings. A design that incorporates a layer of lubricant instead of ball bearings in a hard drive spindle motor, thus providing increased storage capacity, non-operational shock resistance, speed control, robust shipping and handling, and improved acoustics.

FDISK
A software utility that partitions a hard drive.

Femto slider
Form factor in which the read/write head is mounted on the small, lightweight femto slider which allows the head to move more quickly from track to track on the disk.

fetch
The process of retrieving data.

FFS
Free-fall sensor. As an added layer of protection, if the drive (or the system it’s in) is dropped while in use, WD’s free-fall sensor detects that the drive is falling and, in less than 200 milliseconds, parks the head off the disks to help prevent damage and data loss.

FireWire 400
FireWire400 supports data transfer rates up to 400 Mb/s.

FireWire 800
FireWire 800 has a maximum data transfer rate of 800Mb/s. It is backward-compatible with FireWire 400 using an optional adapter.

FireWire®
This high-speed serial bus, also known as IEEE 1394, provides a non-proprietary, high-performance method of interconnecting digital devices.

firmware
Permanent instructions and data programmed directly into the circuitry of read-only memory for controlling computer operations.

FIT
Functional integrity testing. A suite of tests WD performs on all its drive products to ensure compatibility with different hosts, operating systems, adapters, application programs, and peripherals. This testing is performed before a product is released to manufacturing.

flash drive
Compact, portable device that works in a similar way to a hard drive.

flash memory
A special type of portable electronic storage device used for easy and fast information storage in such devices as external hard drives and digital cameras. Examples of flash memory include PCMCIA cards and memory cards for video game consoles.

FlexPower™
Connector technology that accepts power from both industry-standard and new SATA power supplies.

flow control
is the process of managing the rate of data transmission between two nodes to prevent a fast sender from outrunning a slow receiver.

form factor
An industry standard term for the physical and external dimensions of a device.

format
A process that prepares a hard drive to store data.

formatted capacity
The actual capacity available to store data in a mass storage device. The formatted capacity is the gross capacity minus the capacity used by overhead (formatting).

FTP
File Transfer Protocol. A network protocol used to transfer data from one computer to another through a network. FTP is a popular choice for exchanging files independent of the operating systems involved.

full-duplex
A communication protocol that permits simultaneous transmission in both directions.

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Identifying FAT16, FAT32, and NTFS File Systems and partitions

File systems How can I tell what type of file system (FAT16, FAT32, NTFS) my drive is formatted in?

To identify what type of file system the drive is formatted in:

  1. Click on the Start button and select Computer if using Windows Vista, My Computer if using Windows XP or 2000, or Windows Explorer if using Windows Me or 98.
  2. Right-click on the drive letter you want to check.
  3. Click on the Properties option from the pull down menu. A window will appear with the type of file system you have. If you do not see any information regarding FAT16, FAT32, or NTFS in the window that means the drive is formatted in FAT16.

Notes:

  1. Partitions created with the FAT16 file system have a size limitation of 2,048 MB (2.1 GB).
  2. Microsoft first started supporting the FAT32 file system with the release of Windows 95B (a.k.a. OSR2), circa 1997.
  3. When booting from Windows 95A, a Windows 95A startup disk, or any version of MS-DOS, a FAT32 partition will appear as a NON-DOS partition in FDISK.
  4. FAT32 partitions have a theoretical partition size limitation of 2 terabytes (TB). However, new partitions created by either Windows Vista, Windows XP, or Windows 2000 will limit their size to 32 gigabytes (GB). To create partitions greater than 32 GB under Windows Vista, XP, or 2000, you will need to format them using the NTFS file system (or create multiple FAT 32 partitions for drives greater than 32GB).
  5. Windows Vista, Windows XP, Windows 2000, and Windows NT all support the NTFS file system. Windows 2000, XP, and Vista can both support the FAT32 and NTFS file systems, however Windows Vista cannot be installed on a FAT32 partition. Windows NT cannot support FAT32 partitions.
  6. MaxBlast and DiscWizard allow FAT32 partitioning of a drive larger than 32GB.
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FAT 32 File System Frequently Asked Questions

FAT32 File System Microsoft’s FAT32 File System

Windows 95 OSR2 provides an updated version of the File Allocation Table file system called FAT32. This updated file system allows for a default cluster size as small as 4K, as well as support for EIDE hard disc sizes in excess of 2 Gbytes. FAT32 provides many enhancements over previous implementations of the FAT file system.

Cluster & Partition Sizes

FAT32 supports drives up to 2 terabytes in size. FAT32 uses smaller clusters (that is, 4K clusters for drives up to 8 Gbytes in size), resulting in 10 to15 percent more efficient use of disc space relative to large FAT16 partitions. FAT32 will only work on 512 Mbytes and larger drives. Microsoft’s bundled disc tools (Format, FDISK, Defrag, and MS-DOS based ScanDisk) have been revised to work with FAT32.

Note: Please backup all data.

1. QUESTION
When I try to format a FAT32 file system partition larger than 8025 Mbytes from within Windows 95, I receive the following error:

Verifying xxx.xx M
Invalid media or track 0 bad-disk unusable
Format terminated

REASON
This error occurs if there is a non-DOS partition preceding the extended DOS partition and the primary DOS partition has been formatted using the real-mode FORMAT.EXE command.

SOLUTION

  1. Click the “Start” button, click “Shut Down”, click “Restart The Computer In MS- DOS Mode”, and then click “Yes”.
  2. Type format c: (where c is the drive letter for the partition you want to format), and press >ENTER>.
  3. When the format is complete, type exit and press ENTER to restart Windows 95.

2. QUESTION
When I try to partition a drive that is larger than 8 Gbytes in size, the maximum partition size is still 8 Gbytes.

REASON
This can occur if the hard disc controller does not fully support the interrupt 13 extensions. In order for a hard disc that is both larger than 8 Gbytes and using the FAT32 file system to be fully addressed, it must support interrupt 13 extensions. The file IO.SYS tests for the presence of interrupt 13 extensions, and if they are not found, uses the default CHS LBA limit of 7.9 Gbytes. This information applies to both ATA and SCSI hard disc drives.

SOLUTION
Contact the drive controller’s manufacturer for information about a possible BIOS upgrade to a version of the BIOS that fully supports interrupt 13 extensions.

3. QUESTION
When I check in FDISK to see if my partition is FAT32, it only shows FAT16. How do I get my drive to be partitioned in FAT32?

REASON

  1. You are either using the real-mode FDISK, which does not contain the “enable large disk support” prompt, or you did not answer “y” for yes to “enable large disk support”; or
  2. The drive you are attempting to partition with FAT32 is smaller than 512 Mbytes.

SOLUTION
Run the FDISK tool which came with OSR2 on a system with a drive over 512 Mbytes. FDISK will ask whether you wish to enable large disc support. If you answer Yes, any partition you create larger than 512 Mbytes is marked as a FAT32 partition.

4. QUESTION
When I try to dual-boot Windows version 3.x on a computer running Windows OSR2, I receive one of the following error messages:

  • This version of Windows does not run on MS-DOS 6.x or earlier.
  • You started your computer with a version of MS-DOS incompatible with this version of Windows. Insert a Startup diskette matching this version of Windows and then restart.
  • The system has been halted. Press CTRL+ALT+DELETE to restart your computer.
  • This version of Windows cannot be run on this version of DOS.

REASON
Starting with OSR2, dual-booting Windows 3.x is not supported in Windows 95.

SOLUTION
To dual-boot between Windows 3.x and Windows 95, install the retail version of Windows 95. If you have FAT32 partitions, remove them and create a FAT16 partition with the Windows 95 or MS-DOS 6.x version of FDISK.EXE.

Neither MS-DOS 6.x nor the retail version of Windows 95 will recognize a FAT32 volume. Windows 3.x was designed to use the FAT12 and FAT16 file systems. It could potentially damage a FAT32 volume.

5. QUESTION
When I try to compress my drive with DriveSpace or DriveSpace 3, I get the following error:

Drive C cannot be compressed because it is a FAT32 drive.

REASON
DriveSpace was designed to work with the FAT12 and FAT16 file systems and cannot be used with drives using the FAT32 file system.

SOLUTION
None at this time.

6. QUESTION
When I try to defragment a FAT32 partition, I receive the following error:

Windows cannot defragment this drive. Make sure the disk is formatted and free of errors. Then try defragmenting the drive again.

REASON
This can be caused by running an earlier version of DEFRAG.EXE than the version included with OSR2.

SOLUTION
Extract a new copy of the DEFRAG.EXE file from your original OSR2 CD-ROM or discs. For additional information about how to extract or obtain the OSR2 version of DEFRAG.EXE, contact you OEM vendor or Microsoft technical support.

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File Systems

Different operating systems use different file systems. Some are designed specifically to work with more than one, for compatibility reasons; others work only with their own file system. This section takes brief look at the most common operating systems in use on the PC and the file systems that they use. This enables you to know what parts of the rest of the discussion on file systems is most relevant to your situation.

The most common name of the file system, “FAT”, is problematic, even though it is still often used. The first FAT file system used 12-bit file allocation tables; this was later expanded to 16 bits, and became the most common file system implementation for hard disks from the late 1980s to the late 1990s. To distinguish these versions of FAT from the 32-bit successor called FAT32, the older FAT variants are now sometimes called FAT12 or FAT16. However, you will still hear just “FAT” used a lot; if so, you need to find out what specifically is being referred to, if it matters in that particular context. For more elaboration on the differences between FAT12, FAT16 and FAT32.

Throughout my discussion of file systems, I have referred to the FAT family of file systems. This includes several different FAT-related file systems, as described here. The file allocation table or FAT stores information about the clusters on the disk in a table. There are three different varieties of this file allocation table, which vary based on the maximize size of the table. The system utility that you use to partition the disk will normally choose the correct type of FAT for the volume you are using, but sometimes you will be given a choice of which you want to use.

Since each cluster has one entry in the FAT, and these entries are used to hold the cluster number of the next cluster used by the file, the size of the FAT is the limiting factor on how many clusters any disk volume can contain. The following are the three different FAT versions now in use:

  • FAT12: The oldest type of FAT uses a 12-bit binary number to hold the cluster number. A volume formatted using FAT12 can hold a maximum of 4,086 clusters, which is 2^12 minus a few values (to allow for reserved values to be used in the FAT). FAT12 is therefore most suitable for very small volumes, and is used on floppy disks and hard disk partitions smaller than about 16 MB (the latter being rare today.)
  • FAT16: The FAT used for most older systems, and for small partitions on modern systems, uses a 16-bit binary number to hold cluster numbers. When you see someone refer to a “FAT” volume generically, they are usually referring to FAT16, because it is the de facto standard for hard disks, even with FAT32 now more popular than FAT16. A volume using FAT16 can hold a maximum of 65,526 clusters, which is 2^16 less a few values (again for reserved values in the FAT). FAT16 is used for hard disk volumes ranging in size from 16 MB to 2,048 MB. VFAT is a variant of FAT16.
  • FAT32: The newest FAT type, FAT32 is supported by newer versions of Windows, including Windows 95’s OEM SR2 release, as well as Windows 98, Windows ME and Windows 2000. FAT32 uses a 28-bit binary cluster number–not 32, because 4 of the 32 bits are “reserved”. 28 bits is still enough to permit ridiculously huge volumes–FAT32 can theoretically handle volumes with over 268 million clusters, and will support (theoretically) drives up to 2 TB in size. However to do this the size of the FAT grows very large; see here for details on FAT32’s limitations.
  • Here’s a summary table showing how the three types of FAT compare:

     

    Virtual FAT (VFAT)
    Microsoft incorporated several enhancements into the disk management capabilities of Windows 95. Access to the file system can be done using high-speed, protected-mode, 32-bit drivers, or for compatibility, the older DOS 16-bit routines. Support was added for long file names and also for better control over such matters as disk locking, so utilities could access the disk in “exclusive mode” without fear of other programs using it in the meantime.

    Despite the new name and new capabilities, VFAT as a file system is basically the same as FAT is. Most of the new capabilities relate to how the file system is used, and not the actual structures on the disk. VFAT handles standard FAT16 partitions, and under Windows 95 OSR2 or later, FAT32 partitions as well. The only significant change in terms of actual structures is the addition of long file names. Even here, VFAT supports these using what is basically a hack, as opposed to anything really revolutionary.

    With the exception of the long file names, Windows 95, using VFAT, shares the same logical disk structures as DOS or Windows 3.x using FAT.

    NTFS
    The NTFS file system used by Windows NT is completely different from, and incompatible with, the FAT file system that is used by DOS and the other Windows varieties. NTFS can only be used by Windows NT–other operating systems do not have the ability to use a disk formatted with NTFS.
    NTFS is in virtually every way, far superior to FAT. It is a robust, full-featured system that includes file-by-file compression, full permissions control and attribute settings, transaction-based operation, and many more features. It also does not have the problems with cluster sizes and hard disk size limitations that FAT does, and has other performance-enhancing features such as RAID support.

    The only way that NTFS is not superior to FAT is in compatibility with older software. NTFS is not nearly as widely-used as FAT, for this reason. For now I am not including a full examination of NTFS on the site, but I may add this at a later time if it seems warranted.

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