What Are the Attributes of FAT32?
By John Papiewski
An integral part of Microsoft's Windows software, the FAT32 file system allows simplified computer file and folder management. Succeeding the original FAT16 file system and introduced with Windows 95 release 2, FAT32 supports larger files sizes and disk drives. The file system marks each file with six attributes: read-only, hidden, system, volume label, subdirectory and archive.
Capacity and Organization
FAT32 supports hard disks up to 2TB in size, and individual files up to 4GB minus one byte. It organizes a hard disk drive into a hierarchical collection of subdirectories called folders, starting with a root folder. It saves all files in folders, and locates files according to the folder they occupy. Unlike its predecessor, FAT16, FAT32 can move its root folder to any position on the disk.
Read-Only and Hidden
Files marked with the read-only attribute cannot be added to or overwritten, only read. It also prevents deletion of the file by the "del" command, so the attribute's purpose is to prevent accidental changes to important files.
The hidden attribute makes the file invisible to directory searches, unless you explicitly specify you want to see hidden files. It hides confidential files from naive users. These two attributes serve as FAT32's only security. Unlike the more sophisticated NTFS file system, FAT32 does not distinguish between administrators and other types of users.
System and Volume Label
FAT32's system attribute marks critical files used by the Windows operating system. As with the read-only attribute, the system attribute prevents utility programs from altering or deleting the file.
FAT32 can mark one file in the root directory as a volume label. When you initialize a disk drive with the format command, it prompts you for an optional volume name, which helps distinguish the disk's contents. If you type in a volume label, FAT32 creates a file with that as its name and marks it with the volume label attribute.
Subdirectory and Archive
File entries marked with the subdirectory attribute are understood to be directory names and not files. The root directory, such as C:\, can have any number of files and subdirectories, and each subdirectory can, in turn, contain files and subdirectories.
If a program modifies a file, it sets the file's archive attribute. This signals a backup program to copy the file, as the file's content has changed. If the backup program is in "incremental" mode, it does not copy all files, just those with the archive attribute set. Once it copies the files, it clears the attribute.
Chicago native John Papiewski has a physics degree and has been writing since 1991. He has contributed to "Foresight Update," a nanotechnology newsletter from the Foresight Institute. He also contributed to the book, "Nanotechnology: Molecular Speculations on Global Abundance."