Comparison of file systems
From Wikipedia, the free encyclopedia
The following tables compare general and technical information for a number of notable file systems discussed in the linked articles.
|File system||Maximum filename length||Allowable characters in directory entries||Maximum pathname length||Maximum file size||Maximum volume size|
|Acorn ADFS||10 bytes||ISO 8859-1 character except: SPACE $ & % @ \ ^ : . # * " ¦Any||No limit defined||512 MB or 4 GB||512 MB or 4 GB|
|AdvFS||226 characters||Any byte except NUL||No limit defined||16 TB||16 TB|
|Apple DOS 3.x||30 bytes||Any byte except NUL||30 B, no subdirectories (105 files per disk)||Unknown||140 kB DOS 3.3 (assuming standard 35 tracks)
113.75 kB DOS 3.1, 3.2
|Apple ProDOS||15 bytes||A-Z, a-z, 0-9, and period||64 B, including slashes||16 MB||32 MB|
|BFS||255 bytes||Any byte except NUL||No limit defined||260 GB||2 EB|
|Btrfs||255 bytes||Any byte except NUL||Unknown||16 EB||16 EB|
|CBM DOS||16 bytes||Any byte except NUL||Non-hierarchical||16 MB||16 MB|
|CP/M file system||8.3||any byte except: SPACE < > . , ; : = ? * [ ] % | ( ) / \||16 "user areas", no subdirectories||8 MB||8 MB to 512 MB|
|DECtape||6.3||A–Z, 0–9||DTxN:FILNAM.EXT = 15||369280 B (577 * 640)||369920 B (578 * 640)|
|DOS (GEC)||8 bytes||A–Z, 0–9||Non-hierarchical||64 MB||64 MB|
|Elektronika BK tape format||16 bytes||Unknown||Non-hierarchical||64 kB||800 kB (approx) per side for 90 min cassette (limited only by tape length)|
|exFAT||255 characters||Unicode except NULAny||No limit defined||127 PB||64 ZB, 512 TB recommended|
|ext2||255 bytes|| and /Any byte except NUL||No limit defined||2 TB||32 TB|
|ext3||255 bytes|| and /Any byte except NUL||No limit defined||2 TB||32 TB|
|ext3cow||255 bytes|| / and @Any byte except NUL,||No limit defined||2 TB||32 TB|
|ext4||255 bytes|| and /Any byte except NUL||No limit defined||16 TB||1 EB|
|TexFAT||247 characters||Unicode except NULAny||No limit defined||2 GB||500 GB Tested|
|F2FS||255 bytes||Unknown||Unknown||3.94 TB||16 TB|
|FAT12||8.3 (255 UCS-2 code units with VFAT LFNs)||Unicode except NULAny byte except for values 0-31, 127 (DEL) and: " * / : < > ? \ | + , . ; =  (lowcase a-z are stored as A-Z). With VFAT LFN any||No limit defined||32 MB (256 MB)||32 MB (256 MB with 4K sectors and 64 KB clusters)|
|FAT16||8.3 (255 UCS-2 code units with VFAT LFNs)||Unicode except NULAny byte except for values 0-31, 127 (DEL) and: " * / : < > ? \ | + , . ; =  (lowcase a-z are stored as A-Z). With VFAT LFN any||No limit defined||2 GB (4 GB with LFS)||2 GB or 4 GB|
|FAT32||8.3 (255 UCS-2 code units with VFAT LFNs)||Unicode except NULAny byte except for values 0-31, 127 (DEL) and: " * / : < > ? \ | + , . ; =  (lowcase a-z are stored as A-Z). With VFAT LFN any||No limit defined||2 GB (4 GB with LFS)||2 TB (16 TB)|
|FATX||42 bytes||Unicode not permitted.ASCII.||No limit defined||2 GB||2 GB|
|FFS||255 bytes||Any byte except NUL||No limit defined||8 ZB||8 ZB|
|Fossil||65535 bytes of UTF-8 characters||Any Unicode except 0-31||No limit defined||8 EB||Unknown|
|GFS||255||Any byte except NUL||No limit defined||8 EB||8 EB|
|IBM Spectrum Scale||codepoints255 UTF-8|| and /Any byte except NUL||No limit defined||8 EB||8 YB (18 PB tested)|
|HFS||31 bytes||Any byte except :||Unlimited||2 GB||2 TB|
|HFS Plus||255 UTF-16 code units||UnicodeAny valid||Unlimited||8 EB||8 EB|
|HPFS||255 bytes||Any byte except NUL||No limit defined||2 GB||2 TB|
Level 1: 8.3,|
Level 2 & 3: ~ 180
|Depends on Level||~ 180 bytes?||4 GB (Level 1 & 2) to 8 TB (Level 3)||8 TB|
|Joliet ("CDFS")||Unicode characters64||UCS-2 code except * / \ : ; and ?All||Unknown||4 GB (same as ISO 9660:1988)||8 TB (same as ISO 9660:1988)|
|Lanyard Filesystem||255 bytes||Any byte except NUL and /||No limit defined||64 ZB||128 kB to 64 ZB|
|LEAN||4,068 bytes||case sensitive, in UTF-8 (any Unicode codepoint)||No limit defined||8 EB||8 EB|
|Level-D||6.3||A–Z, 0–9||DEVICE:FILNAM.EXT[PROJECT,PROGRM] = 7 + 10 + 15 = 32; + 5*7 for SFDs = 67||24 GB (34,359,738,368 words (235-1); 206,158,430,208 SIXBIT bytes)||12 GB (approx; 64 * 178 MB)|
|Lustre||255 bytes|| and /Any byte except NUL||No limit defined||32 PB (on ext4)||1 YB (55 PB tested)|
|JFS1||255 bytes||Any byte except NUL||No limit defined||8 EB||4 PB|
|JFS||255 bytes||Unicode except NULAny||No limit defined||4 PB||32 PB|
|MFS||255 bytes||Any byte except :||No path (flat filesystem)||226 MB||226 MB|
|MicroDOS file system||14 bytes||Unknown||Unknown||16 MB||32 MB|
|MINIX V1 FS||14 or 30 bytes, set at filesystem creation time||Any byte except NUL||No limit defined||64 MB||64 MB|
|MINIX V2 FS||14 or 30 bytes, set at filesystem creation time||Any byte except NUL||No limit defined||4 GB||1 GB, then 2 TB|
|MINIX V3 FS||60 bytes||Any byte except NUL||No limit defined||4 GB||16 TB|
|NILFS||255 bytes||Any byte except NUL||No limit defined||8 EB||8 EB|
|NSS||226 characters||Depends on namespace used||Only limited by client||8 TB||8 TB|
|NTFS||255 characters||Depends on namespace used||32,767 Unicode characters with each path component (directory or filename) commonly up to 255 characters long||16 EB||16 EB|
|NWFS||80 bytes||Depends on namespace used||No limit defined||4 GB||1 TB|
|OCFS||255 bytes||Any byte except NUL||No limit defined||8 TB||8 TB|
|OCFS2||255 bytes||Any byte except NUL||No limit defined||4 PB||4 PB|
|ODS-5||236 bytes||Unknown||4,096 bytes||2 TB||2 TB|
Period is directory separator
|No limit defined||2 GB||1 GB (at least)|
|PramFS||31 bytes||Any byte except NUL||Unknown||1 GB||8 EB|
|QFS||255 bytes||Any byte except NUL||No limit defined||16 EB||4 PB|
|ReFS||32,767 Unicode characters (255 Unicode characters in Windows 8/8.1)||Unknown||32,767 Unicode characters in each path component||16 EB||1 YB with 64 kB cluster size (264 × 64 × 210). Windows stack addressing allows 16 EB|
|ReiserFS||4,032 bytes/226 characters||Any byte except NUL||No limit defined||8 TB (v3.6), 2 GB (v3.5)||16 TB|
|Reiser4||3,976 bytes||Any byte except / and NUL||No limit defined||8 TB on x86||Unknown|
|Reliance||260 bytes||OS specific||260 B||4 GB||2 TB|
|Reliance Nitro||1,024 bytes||OS specific||1024 bytes||32 TB||32 TB|
|RT-11||6.3||A–Z, 0–9, $||Non-hierarchical||32 MB (65536 * 512)||32 MB|
|UDF||255 bytes||Unicode except NULAny||1,023 bytes||16 EB||2 TB (hard disk), 8 TB (optical disc)|
|UFS1||255 bytes||Any byte except NUL||No limit defined||226 TB||226 TB|
|UFS2||255 bytes||Any byte except NUL||No limit defined||32 PB||1 YB|
|V6FS||14 bytes||NUL and /Any byte except||No limit defined||16 MB||2 TB|
|V7FS||14 bytes||Any byte except NUL and /||No limit defined||1 GB||2 TB|
|VxFS||255 bytes||Any byte except NUL||No limit defined||256 TB||256 TB|
|VMFS2||128||Any byte except NUL and /||2,048||4 TB||64 TB|
|VMFS3||128||Any byte except NUL and /||2,048||2 TB||64 TB|
|XFS||255 bytes||Any byte except NUL||No limit defined||8 EB||8 EB|
|ZFS||255 bytes||Unicode except NULAny||No limit defined||16 EB||256 ZB|
|File system||Maximum filename length||Allowable characters in directory entries||Maximum pathname length||Maximum file size||Maximum volume size|
|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||Max Timestamp Resolution|
|Be File System||Yes||Yes||Yes||No||Unknown||Unknown||No||No||No||No||Yes||No||Unknown|
|CP/M file system||No||No||Yes||No||Unknown||Unknown||No||No||No||No||No||No||Unknown|
|Elektronika BK tape format||No||No||No||No||Unknown||Unknown||No||No||No||No||No||Yes||Unknown|
|HFS Plus||Yes||Yes||Yes||Yes||Yes||No||Yes||Yes||Yes||Yes||Yes||No||1 second|
|Lanyard Filesystem||No||No||Yes||No||Yes||No||Yes||No||No||No||No||No||1 nanosecond|
|Reliance Nitro||Linux port||Linux port||Yes||Yes||Yes||No||No||No||Linux port||No||Yes||Partial||Unknown|
|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||Max Timestamp Resolution|
|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|
|Be File System||No||Yes||No||Yes||Yes||Yes||Unknown||No||No||No||No||No||No||Unknown|
|Btrfs||Yes||Yes||No||No||Yes||Yes||Yes||Yes||No||Planned||Yes||Yes||Yes (on demand)||Online|
|CP/M file system||No||No||No||No||No||No||No||No||No||No||No||No||No||Unknown|
|ext3||Yes||Yes||Yes||Yes||Yes||Yes||No||No||Yes||Yes||No||No||No||Online (can only be shrunk offline)|
|ext4||Yes||Yes||Yes||Yes||Yes||Yes||No||No||Yes||Yes||No||No||No||Online (can only be shrunk offline)|
|FFS||Yes||Yes||No||No||Yes||Yes||No||No||No||No||No||No||No||Offline (cannot be shrunk)|
|JFS||Yes||Yes||No||Yes||Yes||Yes||No||Yes||No||No||No||Unknown||Unknown||Online (cannot be shrunk)|
|Lanyard Filesystem||No||No||No||No||Yes||Yes||No||No||No||No||No||No||No||Offline (cannot be shrunk)|
|Lustre||Yes||Yes||Yes||Yes||Yes||Yes||Yes in 2.0 and later||No||No||No||No||No||No||Online|
|NILFS||Yes||Yes||Yes||No||Yes||Yes||Yes||Yes||No||No||Yes||Unknown||Unknown||Online (since Linux-3.x and nilfs-utils 2.1)|
|NTFS||Yes||Yes||No||Yes||Yes||Yes||Yes||Partial||Yes||Yes||Partial||No||Yes (Windows Server 2012)||Online|
|OCFS2||Yes||Yes||Yes||Yes||Yes||Yes||No||Partial||No||No||Unknown||No||No||Online for version 1.4 and higher|
|Reiser4||Yes||Yes||Yes||No||Yes||Yes||No||Unknown||No||Yes||Yes||No||Unknown||Online (can only be shrunk offline)|
|Reliance Nitro||Yes||Yes||No||No||Depends on OS||Yes||No||No||No||No||Yes||No||No||Unknown|
|UFS2||Yes||Yes||No||No||Yes||Yes||No||Yes||Unknown||No||No||No||No||Offline (cannot be shrunk)|
|XFS||Yes||Yes||Yes||Yes||Yes||Yes||No||No||No||No||No||No||No||Online (cannot be shrunk)|
|ZFS||Yes||Yes||Yes||No||Yes||Yes||No||Yes||No||Yes||Yes||Yes||Yes||Online (cannot be shrunk)|
|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
|File system||Block suballocation||Variable file block size||Extents||Allocate-on-flush||Sparse files||Transparent compression|
|Be File System||No||No||Yes||No||Unknown||No|
|JFS||Yes||No||Yes||No||Yes||only in JFS1 on AIX|
|File system||Block suballocation||Variable file block size||Extents||Allocate-on-flush||Sparse files||Transparent compression|
Supporting operating systems
|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||Plan 9|
|BFS||No||Partial - read-only with third-party driver||Partial - read-only with third-party driver||Partial - read-only||No||Unknown||No||Yes||Unknown||Unknown||Unknown||Unknown||No||No||Unknown||Unknown||No|
|Btrfs||No||No||No||Yes: unstable from kernel 2.6.29 to 3.9; stable since 3.10||No||No||No||No||No||No||No||No||No||No||Unknown||Unknown||No|
|DECtape||No||Unknown||Unknown||with AncientFS||No||with AncientFS||with AncientFS||Unknown||Unknown||Unknown||Unknown||Unknown||No||No||Unknown||Unknown||No|
|exFAT||No||Partial read-only with third party driver||Yes : Win7, Vista SP1, can be added to XP SP2, SP3||with third party driver||No||Partial 10.6.5+, limited to 1024 byte clusters||No||No||Yes||No||No||No||Yes||No||Unknown||Unknown||Unknown|
|ext2||Unknown||Unknown||with Ext2Fsd (complete) or Ext2 IFS (partial, no large inodes) or Ext2Read (read-only, also on LVM2)||Yes since kernel 0.99||No||with ExtFS, fuse-ext2, and ext2fsx||Yes||read-only||Unknown||Unknown||Unknown||third-party app||with 3rd-party app||with 3rd-party app||Unknown||Unknown||Yes|
|ext3||Unknown||Unknown||with Ext2Fsd (complete) or Ext2 IFS (partial, no large inodes) or Ext2Read (read-only, also on LVM2)||Yes since kernel 2.4.15||No||with ExtFS and fuse-ext2||Partial read-only||Unknown||Yes||Unknown||Unknown||Unknown||with 3rd-party app||with 3rd-party app||Unknown||Unknown||No|
|ext3cow||Unknown||Unknown||Unknown||Yes Kernel 2.6.20||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||No|
|ext4||No||No||Partial with Ext2Fsd (partial, extents limited) or Ext2Read (read-only, also on LVM2)||Yes since kernel 2.6.28||No||with ExtFS (full read/write),  fuse-ext2 (partial), and ext4fuse (read-only)||Partial support in kernel since version 10.1 (read-only) or with ext4fuse (read-only)||Unknown||Unknown||Unknown||Unknown||Unknown||No||Unknown||Unknown||Unknown||No|
|FAT12||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes||No||Partial on diskettes only, through dos* commands||Unknown||Yes||Yes||Unknown||Yes||Unknown||Yes|
|FAT16||Yes since DOS 3.0, FAT16B since DOS 3.31||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Partial on diskettes only, through dos* commands||Unknown||Yes||Yes||Yes||Yes||Unknown||Yes|
|FAT32||Yes since DOS 7.1||Yes since Windows 95 OSR2||Yes since Windows 2000||Yes||Yes||Yes||Yes||Yes||Yes||Partial on diskettes only, through dos* commands||Unknown||with third-party app||Yes||Yes||Yes||Unknown||Yes|
|Fossil||No||No||No||with 3rd-party software||No||with 3rd-party software||with 3rd-party software||No||with 3rd-party software||No||No||No||No||No||No||No||Yes|
|GFS||No||Unknown||Unknown||Yes since kernel 2.6.19||No||Unknown||No||Unknown||Unknown||Unknown||Unknown||Unknown||No||No||Unknown||Unknown||No|
|HFS||No||with third-party app||with third-party app||Yes||Yes||Partial: read-only since OSX 10.6||with third-party app||Unknown||Unknown||Unknown||No||with third-party app||No||No||No||Unknown||No|
|HFS Plus||No||with third-party app||with third-party app||Partial - write support occurs if journal is empty, but requires a force mount.||Yes since Mac OS 8.1||Yes||Partial read-only third-party app||Unknown||Unknown||Unknown||No||with third-party app||No||No||No||Unknown||No|
|HPFS||with third-party driver||Partial read-only third-party driver||included until v3.51, third-party driver until 4.0||Yes||No||Unknown||Yes||Unknown||Unknown||Unknown||Unknown||Yes||No||Unknown||Unknown||Unknown||No|
|IBM Spectrum Scale||No||No||Yes||Yes since 2001||No||No||No||No||No||Yes||No||No||No||No||No||No||No|
|LFS||No||Unknown||Unknown||with logfs and others||No||Unknown||No||Unknown||Unknown||Unknown||Unknown||Unknown||No||No||Unknown||Unknown||Unknown|
|Lustre||No||No||Partial - under development||Yes||No||Partial - via FUSE||Partial - via FUSE||No||Partial - under development||No||No||No||No||No||Unknown||Unknown||No|
|NILFS||No||Unknown||Unknown||Yes since kernel 2.6.30||No||Unknown||No||Unknown||Unknown||Unknown||Unknown||Unknown||No||No||Unknown||Unknown||No|
|NSS||Unknown||Unknown||Unknown||with Novell OES2||No||Unknown||No||Unknown||Unknown||Unknown||Unknown||Unknown||No||No||Unknown||Unknown||No|
|NTFS||with third-party driver||with third-party driver||Yes||Yes Kernel 2.2 or newer, or with NTFS-3G or ntfsprogs||with NTFS-3G or MacFUSE||with NTFS-3G or partial read-only in kernel||with NTFS-3G||read-only||with NTFS-3G on Opensolaris||Unknown||Unknown||Partial read-only third-party driver||with 3rd-party driver||No||Unknown||Unknown||Unknown|
|NWFS||Unknown||Unknown||Unknown||via ncpfs client software||No||Unknown||Yes||Unknown||Unknown||Unknown||Unknown||Unknown||No||No||Unknown||Unknown||No|
|ODS-2||No||Unknown||Unknown||Partial read-only with tool or kernel module||No||Unknown||No||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||No|
|ODS-5||No||Unknown||Unknown||Partial read-only with kernel module||No||Unknown||No||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||No|
|QFS||No||Unknown||Unknown||via client software||No||Unknown||No||Unknown||Yes||Unknown||Unknown||Unknown||No||No||Unknown||Unknown||No|
|ReFS||No||No||Yes since Windows Server 2012 and Windows 8.1||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown|
|Reiser4||No||Unknown||Partial with DiskInternals Linux Reader (read-only)||with a kernel patch||No||No||No||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||No|
|ReiserFS||No||Unknown||Partial with DiskInternals Linux Reader (read-only)||Yes since kernel 2.4.1||No||No||Partial - read only||Partial - read only||Unknown||Unknown||Unknown||Unknown||with 3rd-party app||with 3rd-party app||Unknown||Unknown||No|
|UDF||Unknown||Partial read-only support of UDF 1.02 since Win95 OSR2||Yes||Yes||Yes since Mac OS 9||Yes||Yes||Partial||Yes||Unknown||Unknown||Unknown||Yes||Unknown||Unknown||Unknown||No|
|UFS1||No||Unknown||Unknown||Partial - read only||No||Yes||Yes||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||No||Unknown||Unknown|
|UFS2||No||Unknown||Partial - with DiskInternals Linux Reader (read-only)||Partial - read only||No||No||Yes||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||No||Unknown||Unknown|
|VMFS3||No||Unknown||Unknown||Partial read-only with vmfs||Unknown||Unknown||No||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||Unknown||No|
|XFS||No||Unknown||Unknown||Yes since kernel 2.4||No||Unknown||Partial: read-only||Unknown||Unknown||Unknown||Unknown||Unknown||No||No||Unknown||Unknown||No|
|ZFS||No||No||No||with 3rd Party kernel module or FUSE||No||with free 3rd-party software||Yes||No||Yes||No||No||No||Unknown||Unknown||Unknown||Unknown||No|
|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||Plan 9|
- Comparison of archive formats
- Comparison of file archivers
- List of archive formats
- List of file archivers
- List of file systems
- List of default file systems
- List of partition types
- IBM introduced JFS with the initial release of AIX Version 3.1 in 1990. This file system now called JFS1. The new JFS, ported from OS/2 to AIX and Linux, was first shipped in OS/2 Warp Server for e-Business in 1999. It was released as JFS2 on AIX 5L.
- through OEM agreement
- "Polycenter File System — HELP", Tru64 Unix managers, ORNL
- Microsoft first introduced FAT32 in Windows 95 OSR2 (OEM Service Release 2) and then later in Windows 98. NT-based Windows did not have any support for FAT32 up to Windows NT4; Windows 2000 was the first NT-based Windows OS that received the ability to work with it.
- Specifications for the Reliance file systems are available here .
- These are the restrictions imposed by the on-disk 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. Unix-like systems disallow the characters / and NUL in file and directory names across all filesystems.
- 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 128 kB for FAT — which is the cluster size range allowed by the on-disk data structures, although some Installable File System drivers and operating systems do not support cluster sizes larger than 32 kB).
- While the on-disk filesystem structure uses a 4-byte file length, which allows files up to 4G, the usual disk access APIs use the top three bits of the sector number to specify the drive number, effectively limiting the maximum file size to 512M.
- While the on-disk filesystem structure uses a 3-byte sector number, which allows access to 4G of disk space, the usual disk access APIs use the top three bits of the sector number to specify the drive number, effectively limiting the maximum disk size to 512M.
- 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-disk 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.
- The on-disk structures have no inherent limit. Particular Installable File System drivers and operating systems may impose limits of their own, however. MS-DOS/PC DOS do not support full pathnames longer than 66 bytes for FAT12, FAT16 and FAT32 volumes. This limit exists because these operating systems were designed around a fixed-length internal data structure named Current Directory Structure, which holds the absolute paths of the current working directories of all volumes. The FAT12/FAT16 file system implementation under Concurrent DOS and DR DOS 3.31 to 6.0 (prior to 1992 updates) did not impose any such limits on the directory depth due to their internal representation of current working directories as dynamically updated chain of double-linked relative directories. The introduction of a DOS-like CDS (instead of only an emulation thereof) for compatibility purposes with BDOS 7.0 in 1992 imposed the same length limits on PalmDOS, DR DOS 6.0 (since 1992 update), Novell DOS, OpenDOS, etc. as known from MS-DOS/PC DOS. Windows NT does not support full pathnames longer than 32,767 bytes for NTFS. Most Windows programs will fail when full path exceeds 255 characters (including Explorer and CMD.EXE). Linux has a pathname limit of 4,096.
- "ProDOS 8 Technical Reference Manual". Retrieved 31 May 2013.
- Beneath Apple ProDOS (PDF). Quality Software. 1985. pp. 2–8. ISBN 0-912985-05-4.
- Varies wildly according to block size and fragmentation of block allocation groups.
- The CP/M filesystem itself does have limitations in regard to the allowed filename characters to be used, but officially the following characters are not allowed: SPACE < > . , ; : = ? * [ ] % | ( ) / \. CCP reserves the following characters for special purposes: SPACE , = _ . : ;, PIP additionally reserves: < > [ ].
- "Maximum CP/M-80 2.2 volume size?", comp.os.cpm, Google Groups, retrieved 2009-10-09
- Table "Limits" states a maximum of 255 Unicode characters for the filename 
- "KB955704". 2009-01-27.
Description of the exFAT file system driver update package [for 32-bit XP]
- "Interviews/EricSandeen". FedoraProject. 2008-06-09. Retrieved 2009-10-09.
- ext4 1.42 "This release of e2fsprogs has support for file systems > 16 TB"
- "msdn TexFAT File Naming Limitations". 2009-10-14.
- Depends on whether the FAT12, FAT16 or FAT32 implementation has support for long filenames (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 8.3 format of 8-bit characters (space padded in both the basename and extension parts) and may not contain NUL (end-of-directory marker). Short names also do not normally contain lowercase letters. Also note that a few special device names should be avoided, as some operating systems (notably DOS and Windows) effectively reserve them.
- While FAT32 partitions this large work fine once created, some software won't allow creation of FAT32 partitions larger than 32 GB. This includes, notoriously, the Windows XP installation program and the Disk Management console in Windows 2000, XP, 2003 and Vista. Use FDISK from a Windows ME Emergency Boot Disk to avoid. 
- Depends on kernel version and arch. For 2.4 kernels the max is 2 TB. For 32-bit 2.6 kernels it is 16 TB. For 64-bit 2.6 kernels it is 8 EB.
- As Mac OS X is a Unix-like system, which supports : in file names, and which uses / as a pathname component separator, : in file names is represented on disk in HFS and HFS+ as /.
- The Mac OS provides two sets of functions to retrieve file names from an HFS Plus volume, one of them returning the full Unicode names, the other shortened names fitting in the older 31 byte limit to accommodate older applications.
- HFS Plus mandates support for an escape sequence to allow arbitrary Unicode. Users of older software might see the escape sequences instead of the desired characters.
- Docs, Apple
- 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-disk data structure for a directory does not contain entries by those names, but instead contains a special "start" entry. Whilst on-disk directory entries by those names are not physically prohibited, they cannot be created in normal operation, and a directory containing such entries is corrupt.
- This is the limit of the on-disk 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 64 GB.
- ISO 9660#Restrictions
- Through the use of multi-extents, a file can consist of multiple segments, each up to 4 GB in size. See ISO 9660#The 2/4 GB file size limit
- Assuming the typical 2048 Byte sector size. The volume size is specified as a 32-bit value identifying the number of sectors on the volume.
- Joliet Specification
- "LEAN file system". Freedos-32.sourceforge.net. Retrieved 2013-02-05.
- "File, file system, and memory size limits in Minix". Minix1.woodhull.com. Retrieved 2013-02-05.
- NSS allows files to have multiple names, in separate namespaces.
- NTFS allows files to have multiple names, in separate namespaces: Win32, DOS, Win32&DOS, and Posix. Windows APIs create files with Win32 "long" names (1–255 characters), sometimes with an additional "short"/"alias" DOS name in the "8.3" format (12 characters).
- Richard Russon and Yuval Fledel. "NTFS Documentation" (PDF). Retrieved 2011-06-26.
- "Naming Files, Paths, and Namespaces (MSDN Library article)". NB: This article includes discussion of the NT & Win32 namespaces used by Windows APIs; these are distinct from the NTFS filename namespaces.
- In the Win32 namespace, any UTF-16 code unit (case insensitive) except NUL and \ / : * ? " < > | is allowed; in the Posix namespace, any UTF-16 code unit (case sensitive) except NUL and / is allowed; in the DOS namespace, any character in the U+0021–U+007E range except \ / : * ? " < > | is allowed. Windows APIs require Win32 namespace compatibility, which prevents access to folders & files having only Posix names containing Win32-incompatible characters.
- This is the limit of the on-disk structures. The NTFS driver for Windows NT limits the volume size that it can handle to 256 TB and the file size to 16 TB respectively."How NTFS Works".
- Some namespaces had lower name length limits. "LONG" had an 80-byte limit, "NWFS" 80 bytes, "NFS" 40 bytes and "DOS" imposed 8.3 filename.
- Maximum combined filename/filetype length is 236 bytes; each component has an individual maximum length of 255 bytes.
- Maximum pathname length is 4,096 bytes, but quoted limits on individual components add up to 1,664 bytes.
- QFS allows files to exceed the size of disk when used with its integrated HSM, as only part of the file need reside on disk at any one time.
- "MSDN Blogs - Resilient File System, Windows 8 RC's filename length reduced (from 32K to 255) with Windows 8 RTM for NTFS compatibility". Blogs.msdn.com. 2012-01-16. Retrieved 2013-02-05.
- ReiserFS has a theoretical maximum file size of 1 EB, but "page cache limits this to 8TB on architectures with 32 bit int"
- "SFS file system". Publib.boulder.ibm.com. Retrieved 2013-02-05.
- This restriction might be lifted in newer versions.
- 232 × block size
- "Wenguang's Introduction to Universal Disk Format (UDF)". Google Sites. 1 February 2009. Section 5.1 Highlight of the UDF Format. Retrieved 17 July 2014.
- See manual http://wwwlehre.dhbw-stuttgart.de/~helbig/os/v6/doc/V/dir.html
- See manual http://wwwlehre.dhbw-stuttgart.de/~helbig/os/v6/doc/V/fs.html
- See "dir (5)" in Volume 1 of the manual http://cm.bell-labs.com/7thEdMan/
- The actual maximum was 1,082,201,088 bytes, with 10 direct blocks, 1 singly indirect block, 1 doubly indirect block, and 1 triply indirect block. The 4.0BSD and 4.1BSD versions, and the System V version, used 1,024-byte blocks rather than 512-byte blocks, making the maximum 4,311,812,608 bytes or approximately 4 GB.
- Maximum file size on a VMFS volume depends on the block size for that VMFS volume. The figures here are obtained by using the maximum block size.
- Note that the filename can be much longer XFS#Extended attributes
- XFS has a limitation under Linux 2.4 of 64 TB file size, but Linux 2.4 only supports a maximum block size of 2 TB. This limitation is not present under IRIX.
- Implemented in later versions as an extension
- 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.
- ext4 has group descriptor, journal and, starting from Linux kernel 3.5, metadata checksumming
- Concurrent DOS, FlexOS, Multiuser DOS, REAL/32, PalmDOS, Novell DOS, OpenDOS, and DR-DOS can store file owner information in reserved fields of directory entries on FAT12 and FAT16 volumes, if the optional multi-user security module is loaded. If loaded, most external commands invoke support for special /U:owner/group command line options to deal with this extra information.
- Concurrent DOS, FlexOS, Multiuser DOS, REAL/32, DR DOS, PalmDOS, Novell DOS, OpenDOS, and DR-DOS can store read/write/delete/execute access permissions and file/directory passwords in reserved fields of directory entries on FAT12 and FAT16 volumes. This is an integral part of the design, therefore passwords can be appended to file or directory names with semicolon (for example: dirname;dirpwd\filename;filepwd), the PASSWORD command can be used to control permissions and some commands support a special /P:pwd option to deal with this feature.
- File creation and file access timestamps are supported only by DOS 7.0 and higher, and typically only when explicitly enabled.
- Some FAT implementations, such as in Linux, show file modification timestamp (mtime) in the metadata change timestamp (ctime) field. This timestamp is however, not updated on file metadata change.
- Particular Installable File System drivers and operating systems may not support extended attributes on FAT12 and FAT16. The OS/2 and Windows NT filesystem drivers for FAT12 and FAT16 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.
- File permission in 9P are a variation of the traditional Unix permissions with some minor changes, e.g. the suid bit is replaced by a new 'exclusive access' bit.
- "As of 10.5 Leopard, Mac OS X has support for Mandatory Labels. See". Trustedbsd.org. Retrieved 2013-02-05.
- The f-node contains a field for a user identifier. This is not used except by OS/2 Warp Server, however.
- Time the file was recorded on the volume always available; "File Creation Date and Time" available only if the file has an Extended Attribute block.
- Not applicable to file systems on a read-only medium.
- Available only if the file has an Extended Attribute block.
- Creation time is stored in the backing ext4 filesystem, but is not yet sent to clients.
- Lustre has checksums for data over the network, but depends on backing filesystem and hardware for checksums of persistent data
- Not available with ext3/4, but will be available with ZFS OST/MDT backing filesystems.
- NTFS access control lists can express any access policy possible using simple POSIX file permissions (and far more), but use of a POSIX-like interface is not supported without an add-on such as Services for UNIX or Cygwin.
- As of Vista, NTFS has support for Mandatory Labels, which are used to enforce Mandatory Integrity Control. See 
- The local time, timezone/UTC offset, and date are derived from the time settings of the reference/single timesync source in the NDS tree.
- 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.
- 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.
- ocfs2 computes and validates checksums of metadata objects like inodes and directories. It also stores an error correction code capable to fixing single-bite errors.
- Record Management Services (RMS) attributes include record type and size, among many others.
- CRCs are employed for certain types of metadata.
- Access-control lists and MAC labels are layered on top of extended attributes.
- Some operating systems implemented extended attributes as a layer over UFS1 with a parallel backing file (e.g., FreeBSD 4.x).
- MAC/Sensitivity labels are per filesystem. A label per file are not out of the question as a future compatible change but aren't part of any available version of ZFS.
- Solaris "extended attributes" are really full-blown alternate data streams, in both the Solaris UFS and ZFS. ZFS also has "system attributes" used for storing MS-DOS/NTFS compatible attributes for use by CIFS; as well as some attributes ported from FreeBSD
- 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
- Wiki, BTRFS, Deduplication
- Wiki, BTRFS (2015-02-27), duperemove superseed dedup
- Linux kernel versions 2.6.12 and newer.
- Offline growing/shrinking as well as online growing: "Linux man page for resize2fs(8) (from e2fsprogs 1.41.9)".
- Off by default.
- "6", Parted manual, GNU
- "Write Ahead Physical Block Logging" in NetBSD, provides metadata journaling and consistency as an alternative to softdep.
- "OpenBSD growfs(8) manpage". Openbsd.org. 2008-11-28. Retrieved 2013-02-05.
- When used with venti.
- Context based symlinks were supported in GFS, GFS2 only supports standard symlinks since the bind mount feature of the Linux VFS has made context based symlinks obsolete
- Optional journaling of data
- Mac OS System 7 introduced the 'alias', analogous to the POSIX symbolic link but with some notable differences. Not only could they cross file systems but they could point to entirely different file servers, and recorded enough information to allow the remote file system to be mounted on demand. It had its own API that application software had to use to gain their benefits-- this is the opposite approach from POSIX which introduced specific APIs to avoid the symbolic link nature of the link. The Finder displayed their file names in an italic font (at least in Roman scripts), but otherwise they behaved identically to their referent.
- "Hard Links on HFS". Developer.apple.com. Retrieved 2013-02-05.
- Metadata-only journaling was introduced in the Mac OS 10.2.2 HFS Plus driver; journaling is enabled by default on Mac OS 10.3 and later.
- Although often believed to be case sensitive, HFS Plus normally is not. The typical default installation is case-preserving only. From Mac OS 10.3 on the command newfs_hfs -s will create a case-sensitive new file system. HFS Plus version 5 optionally supports case-sensitivity. However, since case-sensitivity is fundamentally different from case-insensitivity, a new signature was required so existing HFS Plus utilities would not see case-sensitivity as a file system error that needed to be corrected. Since the new signature is 'HX', it is often believed this is a new filesystem instead of a simply an upgraded version of HFS Plus. See Apple's File System Comparisons (which hasn't been updated to discuss HFSX) and Technical Note TN1150: HFS Plus Volume Format (which provides a very technical overview of HFS Plus and HFSX).
- Mac OS Tiger (10.4) and late versions of Panther (10.3) provide file change logging (it's a feature of the file system software, not of the volume format, actually). See fslogger.
- As of OS X 10.7, HFS+ supports full volume file encryption known as Filevault 2.
- Since Mac OS X Snow Leopard, online resizing is supported."How to resize a live partition in Snow Leopard and Lion".
- 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.
- [dead link]
- UDF, LFS, and NILFS are log-structured file systems and behave as if the entire file system were a journal.
- Can be shrunk online by migrating files off an OST and removing the OST, or offline with ext3/4 backing filesystems by shrinking the OST filesystem
- 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.
- 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)
- 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.
- NTFS stores everything, even the file data, as meta-data, so its log is closer to block journaling.
- 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.
- NTFS does not internally support snapshots, but in conjunction with the Volume Shadow Copy Service can maintain persistent block differential volume snapshots.
- Rick Vanover. "Windows Server 8 data deduplication". Retrieved 2011-12-02.
- "How to Shrink and Extend NTFS Volumes in Windows". Bleepingcomputer.com. Retrieved 2013-02-05.
- Available only in the "NFS" namespace.
- Limited capability. Volumes can span physical disks (volume segment)
- OCFS2 supports creating multiple write-able snapshots of regular files using REFLINK.
- These are referred to as "aliases".
- Symlinks only visible to NFS clients. References and Off-Disk Pointers (ODPs) provide local equivalent.
- Full block journaling for ReiserFS was not added to Linux 2.6.8 for obvious reasons.[why?]
- Reiser4 supports transparent compression and encryption with the cryptcompress plugin which is the default file handler in version 4.1.
- File system implements reliability via atomic transactions.
- "Soft dependencies" (softdep) in NetBSD, called "soft updates" in FreeBSD provide meta-data consistency at all times without double writes (journaling).
- Block level journals can be added by using gjournal module in FreeBSD.
- "FreeBSD growfs(8) manpage". Freebsd.org. 2012-04-30. Retrieved 2013-02-05.
- System V Release 4, and some other Unix systems, retrofitted symbolic links to their versions of the Version 7 Unix file system, although the original version didn't support them.
- VxFS provides an optional feature called "Storage Checkpoints" which allows for advanced file system snapshots.
- Optionally no on IRIX and Linux.
- 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.
- "How to resize ZFS".
- 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.
- Btrfs can only inline files smaller than 3916B with its metadata"Mailing list discussion".
- only for .REL (record structured) files, up to 254 bytes/record
- Fragments were planned, but never actually implemented on ext2 and ext3.
- 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.
- SuperStor in DR DOS 6.0 and PC DOS 6.1, DoubleSpace in MS-DOS 6.0, DriveSpace in MS-DOS 6.22, Windows 95 and Windows 98, and Stacker in Novell DOS 7, OpenDOS 7.01, DR-DOS 7.02/7.03 and PC DOS 7.0/2000 were data compression schemes for FAT.
- Other block:fragment size ratios supported; 8:1 is typical and recommended by most implementations.
- Only for "stuffed" inodes
- "AIX documentation: JFS data compression". IBM.
- Only if formatted with 4kB-sized clusters or smaller
- Each possible size (in sectors) of file tail has a corresponding suballocation block chain in which all the tails of that size are stored. The overhead of managing suballocation block chains is usually less than the amount of block overhead saved by being able to increase the block size but the process is less efficient if there is not much free disk space.
- In "extents" mode.
- Depends on UDF implementation.
- When enabled, ZFS's logical-block based compression behaves much like tail-packing for the last block of a file.
- Ext2Fsd is an open source ext2/ext3/ext4 kernel-level file system driver for Windows systems (NT/2K/XP/VISTA/7, X86/AMD64) that provides both read/write access to the file system. Currently, does not fully support extents (no size truncating/extending, no file deletion), a default feature of ext4. 
- Ext2 IFS for Windows provides kernel-level read/write access to ext2 and ext3 volumes in Windows NT4, 2000, XP, Vista and Windows 2008. Does not support inodes size above 128 bytes and does not support ext4.
- Ext2Read is an explorer-like utility to explore ext2/ext3/ext4 file systems that provides read-only access to the file system. It supports extents, large inodes, and LVM2 volumes.Ext2Read
- Paragon ExtFS for Mac is a low-level file system driver specially developed to bridge file system incompatibility between Linux and Mac by providing full read/write access to the Ext2, Ext3 and Ext4 file systems under Mac OS X.
- Fuse-ext2 is a multi OS FUSE module to mount ext2 and ext3 file system devices and/or images with read and write support.
- Ext2fsx is the first and old implementation of the Ext2 (Linux) filesystem for Mac OS X.
- OS/2 ext2 Driver
- See Total Commander, which supports accessing ext2, ext3, and ReiserFS from Windows, Windows CE, and Windows Mobile.
- ext4fuse is a free software multi OS FUSE module to mount ext4 file system devices and/or images with read-only support. 
- Files, Databases, and Persistent Storage. MSDN.
- Via dosFs.
- Native FAT32 support with MS-DOS 7.10 and 8.0. Loadable FAT32 support for any DOS since 3.31 with DRFAT32 redirector driver. Native FAT32 support since OEM DR-DOS 7.04, bootable FAT32 support since OEM DR-DOS 7.06. Native FAT32 support with OEM PC DOS 7.10.
- "OS/2 and eComstation FAT32 Driver". Hobbes.nmsu.edu. Retrieved 2013-02-05.
- "How to mount FFS partition under Linux - NetBSD Wiki". Wiki.netbsd.se. Archived from the original on March 19, 2008. Retrieved 2009-10-09.
- Via Plan 9 from User Space; initial checkin "fossil: import from plan 9". Retrieved 2013-11-24.
- Cross-platform Drive Solutions. "Sharing Disks - Windows Products". Macwindows.com. Retrieved 2013-02-05.
- DiskInternals Linux Reader is an application for Windows NT that allows reading of Ext2/3/4, ReiserFS, Reiser4, HFS/HFS+, FAT/exFAT, NTFS, ReFS, and UFS2 filesystems.
- Gagne, Ken (2009-08-31). "Losing legacy data to Snow Leopard". Computerworld. Retrieved 2009-09-07.
- "hfsutils at FreshPorts". Freshports.org. Retrieved 2013-02-05.
- "hfs at FreshPorts". Freshports.org. Retrieved 2013-02-05.
- "OS/2 HFS Driver". Hobbes.nmsu.edu. Retrieved 2013-02-05.
- "Catacombae HFSExplorer". Hem.bredband.net. Retrieved 2013-02-05.
- "DOS/Win 9x HPFS Driver". Hobbes.nmsu.edu. Retrieved 2013-02-05.
- Win NT 4.0 HPFS Driver
- IBM GPFS Product Page
- "NTFS for Windows 98". Download.chip.eu. Retrieved 2013-02-05.
- "OS/2 NTFS Driver". Hobbes.nmsu.edu. Retrieved 2013-02-05.
- Tuxera NTFS for Windows CE. See "article". and announcement.
- Using SAM-QFS on Linux Clients
- "Understanding the difference between the Live File System and Mastered disc formats". Which CD or DVD format should I use?. Microsoft. Retrieved 2008-11-22.
- Native ZFS for Linux
- ZFS on FUSE
- Mac ZFS
- A speed comparison of filesystems on Linux 2.4.5 (archived)
- Filesystems (ext3, reiser, xfs, jfs) comparison on Debian Etch (April 23, 2006)