Support for file systems is highly varied among modern operating systems although there are several common file systems which almost all operating systems include support and drivers for.
Under Linux and UNIX
Many Linux distributions support some or all of ext2, ext3, ReiserFS, Reiser4, GFS, GFS2, OCFS, OCFS2, and NILFS. The ext file systems, namely ext2 and ext3 are based on the original Linux file system. Others have been developed by companies to meet their specific needs, hobbyists, or adapted from UNIX, Microsoft Windows, and other operating systems. Linux has full support for XFS and JFS, along with FAT (the MS-DOS file system), and HFS which is the primary file system for the Macintosh.
In recent years support for Microsoft Windows NT's NTFS file system has appeared in Linux, and is now comparable to the support available for other native UNIX file systems. ISO 9660, and UDF are supported which are standard file systems used on CDs, DVDs, and BluRay discs. It is possible to install Linux on the majority of these file systems. Unlike other operating systems Linux and UNIX allow any file system to be used regardless of the media it is stored on, whether it is a hard drive CD or DVD, or even a contained within a file located on an another file system.
Under Microsoft Windows
Microsoft Windows presently supports NTFS and FAT file systems, along with network file systems shared from other computers, and the ISO 9660 and UDF filesystems used for CDs, DVDs, and other optical discs such as BluRay. Under windows each file system is usually limited in application to certain media, for example CDs must use ISO 9660 or UDF, and as of Windows Vista, NTFS is the only file system which the operating system can be installed on. The NTFS file system is the most efficient and reliable of the Windows file systems, comparing closely in performance to Linux's XFS. Details of its design are not known. Windows Embedded CE 6.0 introduced ExFAT, a file system more suitable for flash drives.
Under Mac OS
Mac OS X supports HFS+ with journaling as its primary file system. It is derived from the Hierarchical File System of the earlier Mac OS. Mac OS X has facilities to read and write FAT, NTFS, UDF, and other file systems, but cannot be installed to them. Due to its UNIX heritage Mac OS X now supports virtually all the file systems supported by the UNIX VFS.
Special Purpose File Systems
FAT file systems are commonly found on floppy discs, flash memory cards, digital cameras, and many other portable devices because of their relative simplicity. Performance of FAT compares poorly to most other file systems as it uses overly simplistic data structures, making file operations time-consuming, and makes poor use of disk space in situations where many small files are present. ISO 9660 and Universal Disk Format are two common formats that target Compact Discs and DVDs. Mount Rainier is a newer extension to UDF supported by Linux 2.6 kernels and Windows Vista that facilitates rewriting to DVDs in the same fashion as has been possible with floppy disks.
Journalized File Systems
File systems may provide journaling, which provides safe recovery in the event of a system crash. A journaled file system writes some information twice: first to the journal, which is a log of file system operations, then to its proper place in the ordinary file system. Journaling is handled by the file system driver, and keeps track of each operation taking place that changes the contents of the disk. In the event of a crash, the system can recover to a consistent state by replaying a portion of the journal. Many UNIX file systems provide journaling including ReiserFS, JFS, and Ext3.
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