User:Pi3832/Relevent File Systems

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Comparison of relevant file systems

The Comparison of file systems page is bloody useless because it lumps all file systems in the known universe together.

So, I've copied it here, and trimmed things that don't come up much in my narrow little view of the world.

Limits

More information File system, Maximum filename length ...

File system	Maximum filename length	Allowable characters in directory entries	Maximum pathname length	Maximum file size	Maximum volume size
FAT16	8.3 (255 UTF-16 code units with LFN)	Any byte except for values 0-31, 127 (DEL) and: " * / : < > ? \ \| + , . ; = [] (lowcase a-z are stored as A-Z). With VFAT LFN any Unicode except NUL	No limit defined	2 GB (4 GB)	2 GB or 4 GB
FAT32	8.3 (255 UTF-16 code units with LFN)	Any byte except for values 0-31, 127 (DEL) and: " * / : < > ? \ \| + , . ; = [] (lowcase a-z are stored as A-Z). With VFAT LFN any Unicode except NULL	No limit defined	4 GB	2 TB (16 TB)
NTFS	255 characters	Any Unicode except NUL and \ / : * ? " < > \|	32,767 Unicode characters with each path component (directory or filename) commonly up to 255 characters long	16 EB	16 EB
ext2	255 bytes	Any byte except NUL and /	No limit defined	2 TB	32 TB
ext3	255 bytes	Any byte except NUL and /	No limit defined	2 TB	32 TB
ext4	256 bytes	Any byte except NUL and /	No limit defined	16 TB	1 EB
ReiserFS	4,032 bytes/226 characters	Any byte except NUL	No limit defined	8 TB (v3.6), 2 GB (v3.5)	16 TB
NILFS	255 bytes	Any byte except NUL	No limit defined	8 EB	8 EB
XFS	255 bytes	Any byte except NUL	No limit defined	8 EB	8 EB
JFS	255 bytes	Any Unicode except NUL	No limit defined	4 PB	32 PB
UDF	255 bytes	Any Unicode except NUL	1,023 bytes	16 EB	Unknown
ZFS	255 bytes	Any Unicode except NUL	No limit defined	16 EB	16 EB
Btrfs	255 bytes	Any byte except NUL	Unknown	16 EB	16 EB
File system	Maximum filename length	Allowable characters in directory entries	Maximum pathname length	Maximum file size	Maximum volume size

Metadata

More information File system, Stores file owner ...

File system	Stores file owner	POSIX file permissions	Creation timestamps	Last access/ read timestamps	Last content modification timestamps	Disk copy created	Last metadata change timestamps	Last archive timestamps	Access control lists	Security/ MAC labels	Extended attributes/ Alternate data streams/ forks	Checksum/ ECC
FAT16	No	No	Partial	Partial	Yes	Yes	No^[1]	No	No	No	No^[2]	No
FAT32	No	No	Partial^[3]	Partial^[3]	Yes	Yes	No^[1]	No	No	No	No	No
NTFS	Yes	Yes	Yes	Yes	Yes	No	Yes	No	Yes	Yes	Yes	No
ext2	Yes	Yes	No	Yes	Yes	Unknown	Yes	No	Yes	Yes	Yes	No
ext3	Yes	Yes	No	Yes	Yes	No	Yes	No	Yes	Yes	Yes	No
ext4	Yes	Yes	Yes	Yes	Yes	Unknown	Yes	No	Yes	Yes	Yes	Partial
NILFS	Yes	Yes	Yes	No	Unknown	Unknown	Yes	No	No	No	No	Yes
ReiserFS	Yes	Yes	No	Yes	Yes	No	No	No	No	No	No	No
Reiser4	Yes	Yes	No	Yes	Yes	Unknown	Yes	No	No	No	No	No
XFS	Yes	Yes	No	Yes	Yes	Unknown	Yes	No	Yes	Yes	Yes	No
JFS	Yes	Yes	Yes	Yes	Yes	Unknown	Yes	No	Yes	Yes	Yes	No
UDF	Yes	Yes	Yes	Yes	Unknown	Unknown	Yes	Yes	Yes	No	Yes	No
ZFS	Yes	Yes	Yes	Yes	Yes	Unknown	Yes	Yes	Yes	Yes	Yes	Yes
Btrfs	Yes	Yes	Yes	Yes	Yes	Unknown	Yes	Unknown	Yes	Yes	Yes	Yes
File system	Stores file owner	POSIX file permissions	Creation timestamps	Last access/read timestamps	Last content modification timestamps	Disk copy created	Last metadata change timestamps	Last archive timestamps	Access control lists	Security/ MAC labels	Extended attributes/ Alternate data streams/ forks	Checksum/ ECC

Features

More information File system, Hard links ...

File system	Hard links	Symbolic links	Block journaling	Metadata-only journaling	Case-sensitive	Case-preserving	File Change Log	Snapshot	XIP	Encryption	COW	integrated LVM	Data deduplication	Volumes are resizeable
FAT16	No	No	No	No	No	Partial	No	No	No	No	No	No	No	Offline^[4]
FAT32	No	No	No	No	No	Partial	No	No	No	No	No	No	No	Offline^[4]
NTFS	Yes	Yes^[5]	No^[6]	Yes^[6]	Yes^[7]	Yes	Yes	Partial^[8]	Yes	Yes	Partial	Unknown	No	Online^[9]
ext2	Yes	Yes	No	No	Yes	Yes	No	No	Yes^[10]	No	No	No	No	Online^[11]
ext3	Yes	Yes	Yes^[12]	Yes	Yes	Yes	No	No	Yes	No	No	No	No	Online^[11]
ext4	Yes	Yes	Yes^[12]	Yes	Yes	Yes	No	No	Yes	No	No	No	No	Online^[11]
NILFS	Yes	Yes	Yes^[13]	No	Yes	Yes	Yes	Yes	No	No	Yes	Unknown	Unknown	Unknown
ReiserFS	Yes	Yes	No^[14]	Yes	Yes	Yes	No	No	No	No	No	No	No	Offline
XFS	Yes	Yes	Yes	Yes	Yes^[15]	Yes	No	No	No	No	No	No	No	Online (cannot be shrunk)
JFS	Yes	Yes	No	Yes	Yes^[16]	Yes	No	Yes	No	No	No	Unknown	Unknown	Online (cannot be shrunk)^[17]
UDF	Yes	Yes	Yes^[13]	Yes^[13]	Yes	Yes	No	No	Yes	No	No	No	No	Unknown
ZFS	Yes	Yes	Yes^[18]	No^[18]	Yes	Yes	No	Yes	No	Yes	Yes	Yes	Yes	Online (cannot be shrunk)^[19]
Btrfs	Yes	Yes	Unknown	Yes	Yes	Yes	Unknown	Yes	No	Planned^[20]	Yes	Yes	Work-in-Progress	Online
File system	Hard links	Symbolic links	Block journaling	Metadata-only journaling	Case-sensitive	Case-preserving	File Change Log	Snapshotting	XIP	Encryption	COW	integrated LVM	Data deduplication	Volumes are resizeable

Allocation and layout policies

More information File system, Block suballocation ...

File system	Block suballocation	Variable file block size^[21]	Extents	Allocate-on-flush	Sparse files	Transparent compression
Btrfs	Yes	No	Yes	Yes	Yes	Yes
FAT16	No	No	No	No	No	No^[22]
FAT32	No	No	No	No	No	No
NTFS	Partial	No	Yes	No	Yes	Partial^[23]
ext2	No^[24]	No	No	No	Yes	No^[25]
ext3	No^[24]	No	No	No	Yes	No
ext4	No^[24]	No	Yes	Yes	Yes	No
NILFS	No	No	No	Yes	Yes	No
ReiserFS	Yes	No	No	No	Yes	No
XFS	No	No	Yes	Yes	Yes	No
JFS	Yes	No	Yes	No	Yes	only in JFS1 on AIX^[26]
UDF	No	No	Yes	Depends^[27]	No	No
ZFS	Partial^[28]	Yes	No	Yes	Yes	Yes
File system	Block suballocation	Variable file block size^[21]	Extents	Allocate-on-flush	Sparse files	Transparent compression

Supporting operating systems

More information File system, DOS ...

File system	DOS	Windows 9x	Windows NT	Linux	Mac OS	Mac OS X	FreeBSD	BeOS	Solaris	AIX	z/OS	OS/2	Windows CE	Windows Mobile	VxWorks	HP-UX
FAT16	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Partial	Unknown	Yes	Yes	Yes	Yes	Unknown
FAT32	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Partial	Unknown		Yes	Yes	Yes	Unknown
NTFS			Yes	Yes	No					Unknown	Unknown	Partial		No	Unknown	Unknown
ext2	Unknown	Unknown		Yes	No		Yes	Unknown	Unknown	Unknown	Unknown				Unknown	Unknown
ext3	Unknown	Unknown		Yes	No		Yes	Unknown	Yes	Unknown	Unknown	Unknown			Unknown	Unknown
ext4	No	No		Yes	No		No	Unknown	Unknown	Unknown	Unknown	Unknown	No	Unknown	Unknown	Unknown
NILFS	No	Unknown	Unknown	Yes	No	Unknown	No	Unknown	Unknown	Unknown	Unknown	Unknown	No	No	Unknown	Unknown
ReiserFS	No	Unknown	Partial	Yes	No	No	Partial	Unknown	Unknown	Unknown	Unknown	Unknown			Unknown	Unknown
XFS	No	Unknown	Unknown	Yes	No	Unknown	Partial	Unknown	Unknown	Unknown	Unknown	Unknown	No	No	Unknown	Unknown
JFS	No	Unknown	Unknown	Yes	No	No	No	Unknown	Unknown	Yes	Unknown	Yes	No	No	Unknown
UDF	Unknown	Partial	Yes	Yes	Yes	Yes	Yes	Unknown	Yes	Unknown	Unknown	Unknown	Yes	Unknown	Unknown	Unknown
ZFS	No	No	No		No		Yes	No	Yes	No	No	No	Unknown	Unknown	Unknown	Unknown
Btrfs	No	No	No	Yes	No	No	No	No	No	No	No	No	No	No	Unknown	Unknown
File system	DOS	Windows 9x	Windows NT	Linux	Mac OS	Mac OS X	FreeBSD	BeOS	Solaris	AIX	z/OS	OS/2	Windows CE	Windows Mobile	VxWorks	HP-UX

[1]
[2]
[3]
[4]
[5]
As of Windows Vista, NTFS fully supports soft links. See this Microsoft article on Vista kernel improvements. NTFS 5.0 (Windows 2000) and higher can create junctions, which allow any valid local directory (but not individual files) ("target" of junction) to be mapped to an NTFS version thereof ("source" = location of junction). The source directory must lie on an NTFS 5+ partition, but the target directory can lie on any valid local partition and needn't be NTFS. Junctions are implemented through reparse points, which allow the normal process of filename resolution to be extended in a flexible manner.
[6]
NTFS stores everything, even the file data, as meta-data, so its log is closer to block journaling.
[7]
While NTFS itself supports case sensitivity, the Win32 environment subsystem cannot create files whose names differ only by case for compatibility reasons. When a file is opened for writing, if there is any existing file whose name is a case-insensitive match for the new file, the existing file is truncated and opened for writing instead of a new file with a different name being created. Other subsystems like e. g. Services for Unix, that operate directly above the kernel and not on top of Win32 can have case-sensitivity.
[8]
NTFS does not internally support snapshots, but in conjunction with the Volume Shadow Copy Service can maintain persistent block differential volume snapshots.
[9]
http://www.bleepingcomputer.com/tutorials/tutorial133.html
[10]
Linux kernel versions 2.6.12 and newer.
[11]
Offline growing/shrinking as well as online growing: "Linux man page for resize2fs(8) (from e2fsprogs 1.41.9)".
[12]
Off by default.
[13]
[14]
Full block journaling for ReiserFS was not added to Linux 2.6.8 for obvious reasons.
[15]
Optionally no on IRIX.
[16]
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.
[17]
http://www.linux.com/archive/feed/32002
[18]
ZFS is a transactional filesystem using copy-on-write semantics, guaranteeing an always-consistent on-disk state without the use of a traditional journal. However, it does also implement an intent log to provide better performance when synchronous writes are requested.
[19]
"How to resize ZFS".
[20]
McPherson, Amanda (2009-06-22), A Conversation with Chris Mason on BTRfs: the next generation file system for Linux, Linux Foundation, retrieved 2009-09-01
[21]
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.
[22]
[23]
Only if formatted with 4kB-sized clusters or smaller
[24]
Fragments were planned, but never actually implemented on ext2 and ext3.
[25]
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.
[26]
"AIX documentation: JFS data compression". IBM.
[27]
Depends on UDF implementation.
[28]
When enabled, ZFS's logical-block based compression behaves much like tail-packing for the last block of a file.

Limits

Metadata

Features

Allocation and layout policies

Supporting operating systems

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