File system

The following tables compare general and technical information for a number of file systems. Please see the individual file system articles for further information.

General Information

	Creator	Introduced in	Original operating system
FS	Bell Labs	1972	Unix
FAT12	Microsoft	1980	QDOS
FAT16	Microsoft	1983	MS-DOS version 2
MFS	Apple	1984	Mac OS
HFS	Apple	1985	Mac OS
OFS Template:Fn	Metacomco for Commodore	1985	Amiga OS
FAT32	Microsoft	1996	Windows 95b Template:Fn
HPFS	IBM & Microsoft	1988	OS/2
NTFS	Microsoft, Gary Kimura, Tom Miller	1993?	Windows NT
HFS+	Apple	1998	Mac OS
FFS	Kirk McKusick	1983	4.2BSD
FFS (Amiga)	Commodore	1987	AmigaOS 1.3
UFS1	Kirk McKusick	1994	4.4BSD
UFS2	Kirk McKusick	2002	FreeBSD 5.0
LFS	Margo Seltzer	1993	4.4BSD
Mac OS X UFS	Apple (from UFS1)	?	Mac OS X
ext2	Rémy Card	1993	Linux
ext3	Stephen Tweedie	1999	Linux
ReiserFS	Namesys	2001	Linux
Reiser4	Namesys	2005	Linux
XFS	SGI	1994	IRIX
JFS	IBM	1990	AIX Template:Fn
JFS2	IBM	1999	OS/2 WSeB
Be File System	Be Inc., D. Giampaolo, C. Meurillon	1996?	BeOS
NSS	Novell	1998	Netware 5
NWFS	Novell	1985	Netware 286
ODS5	DEC	?	VMS
UDF	ISO/ECMA/OSTA	1995	-
VxFS	VERITAS	1991	SVR4.0
	Creator	Introduced in	Original operating system

Limits

	Maximum filename length	Allowable characters in directory entriesTemplate:Fn	Maximum pathname length	Maximum file size	Maximum volume size Template:Fn
FAT12	255 bytes Template:Fn	Any Unicode except NUL Template:Fn Template:Fn	No limit defined Template:Fn	4GiB	1MiB to 512MiB
FAT16	255 bytes Template:Fn	Any Unicode except NUL Template:Fn Template:Fn	No limit defined Template:Fn	4GiB	16MiB to 2GiB
FAT32	255 bytes Template:Fn	Any Unicode except NUL Template:Fn Template:Fn	No limit defined Template:Fn	4GiB	512MiB to 2TiB Template:Fn
HPFS	255 bytes	Any byte except NUL Template:Fn	No limit defined Template:Fn	4GiB	2TiB Template:Fn
NTFS	255 bytes	Any Unicode except NUL	No limit defined Template:Fn	16EiB	16EiB
HFS+	255 charactersTemplate:Fn	Any Unicode except NUL Template:Fn Template:Fn	?	8EiB	8EiB
FFS	255 bytes	Any byte except NUL Template:Fn	No limit defined Template:Fn	4GiB	256TiB
UFS1	255 bytes	Any byte except NUL Template:Fn	No limit defined Template:Fn	4GiB to 256TiB	256TiB
UFS2	255 bytes	Any byte except NUL Template:Fn	No limit defined Template:Fn	512GiB to 32PiB	1YiB
Mac OS X UFS	?	Any byte except NUL Template:Fn	?	?	?
ext2	255 bytes	Any byte except NUL Template:Fn	No limit defined Template:Fn	16GiB to 2TiB Template:Fn	2TiB to 32TiB
ext3	255 bytes	Any byte except NUL Template:Fn	No limit defined Template:Fn	16GiB to 2TiB Template:Fn	2TiB to 32TiB
ReiserFS	4032 bytes/255 characters	Any byte except NUL Template:Fn	No limit defined Template:Fn	8TiB Template:Fn	16TiB
Reiser4	?	?	No limit defined Template:Fn	8TiB on x86	?
XFS	255 bytes	Any byte except NUL Template:Fn	No limit defined Template:Fn	9EiB Template:Fn	9EiB Template:Fn
JFS	255 bytes	Any byte except NUL Template:Fn	No limit defined Template:Fn	8EiB	512TiB to 4PiB
JFS2	255 bytes	Any Unicode except NUL	No limit defined Template:Fn	4PiB	32PiB
Be File System	255 bytes	Any byte except NUL Template:Fn	No limit defined Template:Fn	12288 bytes to 260GiB Template:Fn	256PiB to 2EiB
NSS	?	Depends on namespace used Template:Fn	Only limited by client	8TiB	8TiB
NWFS	80 bytes Template:Fn	Depends on namespace used Template:Fn	No limit defined Template:Fn	4GiB	1TiB
ODS5	236 bytesTemplate:Fn	?	4096 bytesTemplate:Fn	1TiB	1TiB
VxFS	255 bytes	Any byte except NUL Template:Fn	No limit defined Template:Fn	16EiB	?
UDF	255 bytes	Any Unicode except NUL	1023 bytes Template:Fn	16EiB	?
	Maximum filename length	Allowable characters in directory entriesTemplate:Fn	Maximum pathname length	Maximum file size	Maximum volume size Template:Fn

Metadata

	Rich File type metadata	Stores file owner	POSIX file permissions	Creation timestamps	Last access/read timestamps	Last metadata change timestamps	Last archive timestamps	Access control lists	Security/MAC labels	Alternate data stream/fork
FAT12	No Template:Fn	No	No	Yes	Yes	No	No	No	No	No
FAT16	No Template:Fn	No	No	Yes	Yes	No	No	No	No	No
FAT32	No Template:Fn	No	No	Yes	Yes	No	No	No	No	No
HPFS	Yes	YesTemplate:Fn	No	Yes	Yes	No	No	No	?	No
NTFS	Yes	Yes	NoTemplate:Fn	Yes	Yes	Yes	No	Yes	?	Yes
HFS+	Partial	Yes	Yes	Yes	Yes	Yes	?	Yes	?	Yes
FFS	No	Yes	Yes	No	Yes	Yes	No	No	No	No
UFS1	No Template:Fn	Yes	Yes	No	Yes	Yes	No	No Template:Fn	No Template:Fn	No
UFS2	Yes Template:Fn	Yes	Yes	Yes	Yes	Yes	No	No Template:Fn	No Template:Fn	No
LFS	No	Yes	Yes	No	Yes	Yes	No	No	No	No
Mac OS X UFS	Partial	Yes	Yes	No	Yes	Yes	No	No	No	No
ext2	Yes Template:Fn	Yes	Yes	No	Yes	Yes	No	Yes Template:Fn	Yes Template:Fn	No
ext3	Yes Template:Fn	Yes	Yes	No	Yes	Yes	No	Yes Template:Fn	Yes Template:Fn	No
ReiserFS	Yes Template:Fn	Yes	Yes	No	Yes	Yes	No	Yes Template:Fn	Yes Template:Fn	No
Reiser4	No	Yes	Yes	No	Yes	Yes	No	No	No	No
XFS	Yes	Yes	Yes	No	Yes	Yes	No	Yes	Yes Template:Fn	No
JFS	Yes Template:Fn	Yes	Yes	No	Yes	Yes	No	Yes	?	No
Be File System	Yes	Yes	Yes	Yes	No	No	No	No	No	Yes
NSS	Yes Template:Fn	Yes	Yes	YesTemplate:Fn	YesTemplate:Fn	Yes	YesTemplate:Fn	Yes	?	YesTemplate:Fn
NWFS	Yes Template:Fn	Yes	?	YesTemplate:Fn	YesTemplate:Fn	Yes	YesTemplate:Fn	Yes	?	YesTemplate:Fn
ODS5	Yes Template:Fn	Yes	Yes	?	?	?	?	Yes	?	No
VxFS	Yes Template:Fn	Yes	Yes	Yes	Yes	Yes	No	Yes	?	Yes
UDF	No	Yes	Yes	Yes	Yes	Yes	No	Yes	No	Yes
	Rich File type metadata	Stores file owner	POSIX file permissions	Creation timestamps	Last access/read timestamps	Last metadata change timestamps	Last archive timestamps	Access control lists	Security/MAC labels	Alternate data stream/fork

Features

	Hard links	Soft links	Block journaling	Metadata-only journaling	Case-sensitive	Case-preserving	File Change Log
FAT12	No	No	No	No	No	No	No
FAT16	No	No	No	No	No	Partial	No
FAT32	No	No	No	No	No	Partial	No
HPFS	No	No	No	No	No	Yes	No
NTFS	Yes	YesTemplate:Fn	PartialTemplate:Fn	Yes	YesTemplate:Fn	Yes	Yes
HFS+	Yes	Yes	No	YesTemplate:Fn	YesTemplate:Fn	Yes	No
FFS	Yes	Yes	No	No	Yes	Yes	No
UFS1	Yes	Yes	No	No	Yes	Yes	No
UFS2	Yes	Yes	No	No	Yes	Yes	No
LFS	Yes	Yes	YesTemplate:Fn	YesTemplate:Fn	Yes	Yes	No
Mac OS X UFS	Yes	Yes	No	No	Yes	Yes	No
ext2	Yes	Yes	No	No	Yes	Yes	No
ext3	Yes	Yes	Yes	Yes	Yes	Yes	No
ReiserFS	Yes	Yes	Yes Template:Fn	Yes	Yes	Yes	No
Reiser4	Yes	Yes	Yes	No	Yes	Yes	No
XFS	Yes	Yes	No	Yes	Yes Template:Fn	Yes	Yes
JFS	Yes	Yes	No	Yes	YesTemplate:Fn	Yes	No
Be File System	Yes	Yes	No	Yes	Yes	Yes	?
NSS	Yes	Yes	?	Yes	YesTemplate:Fn	YesTemplate:Fn	YesTemplate:Fn
NWFS	YesTemplate:Fn	YesTemplate:Fn	No	No	YesTemplate:Fn	YesTemplate:Fn	YesTemplate:Fn
ODS5	Yes	YesTemplate:Fn	No	Yes	No	Yes	Yes
UDF	Yes	Yes	YesTemplate:Fn	YesTemplate:Fn	Yes	Yes	No
VxFS	Yes	Yes	Yes	No	Yes	Yes	Yes
	Hard links	Soft links	Block journaling	Metadata-only journaling	Case-sensitive	Case-preserving	File Change Log

Allocation and layout policies

	Tail packing	Data compression	Block fragmentation	Delayed allocation	Extents	Variable file block size Template:Fn	Block suballocation Template:Fn
FAT12	No	No Template:Fn	No	No	No	No	No
FAT16	No	No Template:Fn	No	No	No	No	No
FAT32	No	No Template:Fn	No	No	No	No	No
HPFS	No	No	No	No	Yes	No	?
NTFS	No	Yes	Partial	No	Yes	No	No
HFS+	No	No	?	No	No	No	?
FFS	No	No	8:1 Template:Fn	No	No	No	No
UFS1	No	No	8:1 Template:Fn	No	No	No	No
UFS2	No	No	8:1 Template:Fn	No	No	Yes	No
LFS	No	No	8:1 Template:Fn	No	No	No	No
Mac OS X UFS	No	No	8:1 Template:Fn	No	No	No	No
ext2	No	No Template:Fn	No Template:Fn	No	No	No	No
ext3	No	No	No Template:Fn	No	No	No	No
ReiserFS	Yes	No	No	No	No	No	No
Reiser4	Yes	No Template:Fn	No	Yes	Yes Template:Fn	No	No
XFS	No	No	No	Yes	Yes	No	No
JFS	No	No	?	No	Yes	No	?
Be File System	No	No	?	No	No	?	?
NSS	No	Yes	?	No	No	No	No
NWFS	No	Yes	?	No	No	No	Yes
ODS5	No	No	No	No	No	No	No
VxFS	No	No	?	No	Yes	No	?
UDF	No	No	No	? Template:Fn	Yes	No	No
	Tail packing	Data compression	Block fragmentation	Delayed allocation	Extents	Variable block size Template:Fn	Block Suballocation

Notes

Template:Fnb HFS, an older version of HFS+, only supported 31 character filenames; some older applications don't work well with names longer than this.
Template:Fnb HFS+ mandates support for an escape sequence to allow arbitrary Unicode. Users of older software might see the escape sequences instead of the desired characters.
Template:Fnb Varies wildly according to block size and fragmentation of block allocation groups.
Template:Fnb For filesystems that have variable allocation unit (block/cluster) sizes, a range of size are given, indicating the maximum volume sizes for the minimum and the maximum possible allocation unit sizes of the filesystem (e.g. 512 bytes and 128KiB for FAT — which is the cluster size range allowed by the on-disc data structures, although some Installable File System drivers and operating systems do not support cluster sizes larger than 32KiB).
Template:Fnb NTFS access control lists can express essentially any access policy possible using simple POSIX file permissions, but use of a POSIX-like interface is not supported without an add-on such as Services for UNIX or Cygwin.
Template:Fnb The file change logs, last entry change timestamps, and other filesystem metadata, are all part of the extensive suite of auditing capabilities built into NDS/eDirectory called NSure Audit. (Filesystem Events tracked by NSure)
Template:Fnb While FAT32 partitions this large work fine once created, some software won't allow creation of FAT32 partitions larger than 32GiB. This includes, notoriously, the Windows XP installation program.
Template:Fnb ReiserFS has a theoretical maximum file size of 1EiB, but "page cache limits this to 8 Ti on architectures with 32 bit int"[1]
Template:Fnb XFS has a limitation under Linux 2.4 of 64TiB file size and 2TiB file system size. This limitation is not present under IRIX.
Template:Fnb Microsoft first introduced FAT32 in Windows 95 OSR2 (OEM Service Release 2) and then later in Windows 98.
Template:Fnb IBM introduced JFS with the initial release of AIX Version 3.1 in 1990. This file system now called JFS1. The new JFS (sometimes called JFS2), on which the Linux port was based, was first shipped in OS/2 Warp Server for e-Business in 1999.
Template:Fnb The on-disc structures have no inherent limit. Particular Installable File System drivers and operating systems may impose limits of their own, however. MS-DOS does not support full pathnames longer than 260 bytes for FAT12 and FAT16. Windows NT does not support full pathnames longer than 32767 bytes for NTFS.
Template:Fnb This is the limit of the on-disc structures. The HPFS Installable File System driver for OS/2 uses the top 5 bits of the volume sector number for its own use, limiting the volume size that it can handle to 64GiB.
Template:Fnb The f-node contains a field for a user identifier. This is not used except by OS/2 Warp Server, however.
Template:Fnb Maximum combined filename/filetype length is 236 bytes; each component has an individual maximum length of 255 byes.
Template:Fnb Maximum pathname length is 4096 bytes, but quoted limits on individual components add up to 1664 bytes.
Template:Fnb Record Management Services (RMS) attributes include record type and size, among many others.
Template:Fnb These are referred to as "aliases".
Template:Fnb Novell calls this feature "multiple data streams". Published specifications say that NWFS allows for 16 attributes and 10 data streams, and NSS allows for unlimited quantities of both.
Template:Fnb Case-sensitivity/Preservation depends on client. Windows, DOS, and OS/2 clients don't see/keep case differences, whereas clients accessing via NFS or AFP may.
Template:Fnb Published specs say that the 128-bit file system provides for up to 2⁶⁴ bytes to describe the file system, file size, directory entries, etc, with a theoretical max of 2¹²⁸ bytes total to describe all storage on such a machine.
Template:Fnb Particular Installable File System drivers and operating systems may not support extended attributes on FAT12, FAT16, and FAT32. The OS/2 and Windows NT filesystem drivers for FAT12, FAT16, and FAT32 support extended attributes (using a "EA DATA. SF" pseudo-file to reserve the clusters allocated to them). Other filesystem drivers for other operating systems do not.
Template:Fnb Some Installable File System drivers and operating systems may not support extended attributes, access control lists or security labels on these filesystems. Linux kernels prior to 2.6.x may either be missing support for these altogether or require a patch.
Template:Fnb Depends on whether the FAT12, FAT16, and FAT32 implementation has support for LFNs. Where it does not, as in OS/2, MS-DOS, Windows 95, Windows 98 in DOS-only mode and the Linux "msdos" driver, file names are limited to 11 8-bit characters (space padded in both the basename and extension parts) and may not contain NUL (end-of-directory marker) or character 229 (deleted-file marker). Short names also do not normally contain lowercase letters.
Template:Fnb These are the restrictions imposed by the on-disc directory entry structures themselves. Particular Installable File System drivers may place restrictions of their own on file and directory names; and particular and operating systems may also place restrictions of their own, across all filesystems. MS-DOS, Microsoft Windows, and OS/2 disallow the characters \ / : ? * " > < | and NUL in file and directory names across all filesystems. Unices and Linux disallow the characters / and NUL in file and directory names across all filesystems.
Template:Fnb In these filesystems the directory entries named "." and ".." have special status. Directory entries with these names are not prohibited, and indeed exist as normal directory entries in the on-disc data structures. However, they are mandatory directory entries, with mandatory values, that are automatically created in each directory when it is created; and directories without them are considered corrupt.
Template:Fnb The "." and ".." directory entries in HPFS that are seen by applications programs are a partial fiction created by the Installable File System drivers. The on-disc data structure for a directory does not contain entries by those names, but instead contains a special "start" entry. Whilst on-disc directory entries by those names are not physically prohibited, they cannot be created in normal operation, and a directory containing such entries is corrupt.
Template:Fnb NSS allows files to have multiple names, in separate namespaces.
Template:Fnb Some file and directory metadata is stored on the Netware server irrespective of whether Directory Services is installed or not, like date/time of creation, file size, purge status, etc; and some file and directory metadata is stored in NDS/eDirectory, like file/object permissions, ownership, etc.
Template:Fnb Particular Installable File System drivers and operating systems may not support case sensitivity for JFS. OS/2 does not, and Linux has a mount option for disabling case sensitivity.
Template:Fnb The local time, timezone/UTC offset, and date are derived from the time settings of the reference/single timesync source in the NDS tree.
Template:Fnb Some operating systems implemented extended attributes as a layer over UFS1 with a parallel backing file (e.g., FreeBSD 4.x).
Template:Fnb Access-control lists and MAC labels available as an operating-system feature layered on top of extended attributes.
Template:Fnb NTFS 5.0 and higher can create junctions, which allow entire directories (but not individual files) to be mapped to elsewhere in the directory tree of a locally managed drive. These are implemented through reparse points, which allow the normal process of filename resolution to be extended in a flexible manner.
Template:Fnb Turned off by default.
Template:Fnb While NTFS itself supports case sensitivity, the Windows standard file system drivers cannot create files whose names differ only by case, for compatibility reasons.
Template:Fnb NTFS stores everything, even the file data, as meta-data, so its log is closer to block journaling.
Template:Fnb UDF and LFS are log-structured file systems and behave as if the entire file system were a journal.
Template:Fnb In "extents" mode.
Template:Fnb Optionally no on IRIX.
Template:Fnb Variable block size refers to systems which support different block sizes on a per-file basis. (This is similar to extents but a slightly different implementational choice.) The current implementation in UFS2 is read-only.
Template:Fnb Block suballocation divides storage into blocks of 4KiB to 64KiB (usually 8KiB), and if all of the block is not used, the remainder is subdivided into 512-byte blocks for other files, usually smaller files, to use.
Template:Fnb This restriction might be lifted in newer versions.
Template:Fnb Full block journaling for ReiserFS was added to Linux 2.6.8.
Template:Fnb Other block:fragment size ratios supported; 8:1 is typical and recommended by most implementations.
Template:Fnb Depends on UDF implementation.
Template:Fnb Fragments were planned, but never actually implemented on ext2 and ext3.
Template:Fnb Metadata-only journaling was introduced in the Mac OS 10.2.2 HFS+ driver; journaling is enabled by default on Mac OS 10.3 and later.
Template:Fnb e2compr, a set of patches providing block-based compression for ext2, has been available since 1997, but has never been merged into the mainline Linux kernel.
Template:Fnb Reiser4 implements data compression, but has not provided an VFS API for it.
Template:Fnb DoubleSpace in DOS 6, and DriveSpace in Windows 95 and Windows 98 were data compression schemes for FAT, but are no longer supported by Microsoft.
Template:Fnb Some namespaces had lower name length limits. "LONG" had an 80-byte limit, "NTFS" 80 bytes, "NFS" 40 bytes and "DOS" imposed 8.3-style names.
Template:Fnb Available only in the "NFS" namespace.
Template:Fnb Metacomco released a so called "evolution" version of original file system for Amiga realizied by engineers of first Amiga Inc. (Formerly Hi-Toro) in 1982-83/85. To be true, Metacomco made a huge mess of early FS ruining its simple and easy structure. Originally OFS it was simply Amiga File System. Name changed since the release of the "new" Fast File System, born in 1987 for the same platform.

References

Template:Web reference author
Template:Web reference author
"Attribute - $EA_INFORMATION (0xD0)". NTFS Information, Linux-NTFS Project. February 9. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help)
"Attribute - $EA (0xE0)". NTFS Information, Linux-NTFS Project. February 9. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help)
"Attribute - $STANDARD_INFORMATION (0x10)". NTFS Information, Linux-NTFS Project. February 21. {{cite web}}: Check date values in: |date= and |year= / |date= mismatch (help)

External links