Comparison of file systems
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The following tables compare general and technical information for a number of file systems.
General information[edit]
Limits[edit]
File system | Maximum filename length | Allowable characters in directory entries[c] | Maximum pathname length | Maximum file size | Maximum volume size[d] | Max number of files |
---|---|---|---|---|---|---|
BeeGFS | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 16 EB | 16 EB | ? |
CP/M file system | 8.3 | ASCII except for < > . , ; : = ? * [ ] | No directory hierarchy (but accessibility of files depends on user areas via USER command since CP/M 2.2) | 32 MB | 512 MB | ? |
IBM SFS | 8.8 | ? | ? | Non-hierarchical[8] | ? | ? |
DECtape | 6.3 | A–Z, 0–9 | DTxN:FILNAM.EXT = 15 | 369,280 bytes (577 * 640) | 369,920 bytes (578 * 640) | ? |
Elektronika BK tape format | 16 bytes | ? | No directory hierarchy | 64 KB | Not limited. Approx. 800 KB (one side) for 90 min cassette | ? |
MicroDOS file system | 14 bytes | ? | ? | 16 MB | 32 MB | ? |
Level-D | 6.3 | A–Z, 0–9 | DEVICE:FILNAM.EXT[PROJCT,PROGRM] = 7 + 10 + 15 = 32; + 5*7 for SFDs = 67 | 34,359,738,368 words (2**35-1); 206,158,430,208 SIXBIT bytes | Approx 12 GB (64 * 178 MB) | ? |
RT-11 | 6.3 | A–Z, 0–9, $ | 0 (no directory hierarchy) | 33,554,432 bytes (65536 * 512) | 33,554,432 bytes | ? |
Version 6 Unix file system (V6FS) | 14 bytes | Any byte except NUL and / [e]
|
No limit defined[f] | 16 MB[g] | 32 MB | ? |
Disk Operating System (GEC DOS) | ? | ? | ? | ? at least 131,072 bytes | ? | ? |
GEC DOS filing system extended | 8 bytes | A–Z, 0–9. Period was directory separator | ? No limit defined (workaround for OS limit) | ? at least 131,072 bytes | ? | ? |
CBM DOS | 16 bytes | Any byte except NUL | 0 (no directory hierarchy) | 16 MB | 16 MB | ? |
Version 7 Unix file system (V7FS) | 14 bytes | Any byte except NUL or / [e]
|
No limit defined[f] | 1 GB[h] | 2 TB | ? |
exFAT | 255 UTF-16 characters | ? | 32,760 Unicode characters with each path component no more than 255 characters[11] | 16 EB[11] | 64 ZB (276 bytes) | ? |
FAT (8-bit) | 6.3 (binary files) / 9 characters (ASCII files) | ASCII (0x00 and 0xFF not allowed in first character) | No directory hierarchy | ? | ? | ? |
FAT12/FAT16 | 8.3 (255 UCS-2 characters with LFN)[i] | SFN: OEM A-Z, 0-9, ! # $ % & ' ( ) - @ ^ _ ` { } ~, 0x80-0xFF, 0x20. LFN: Unicode except NUL, " * / : < > ? \ | [c][e] | No limit defined[f] | 32 MB (4 GB)[j] | 1 MB to 32 MB | ? |
FAT16B/FAT16X | 8.3 (255 UCS-2 characters with LFN)[i] | SFN: OEM A-Z, 0-9, ! # $ % & ' ( ) - @ ^ _ ` { } ~, 0x80-0xFF, 0x20. LFN: Unicode except NUL, " * / : < > ? \ | [c][i][e] | No limit defined[f] | 2 (4) GB[j] | 16 MB to 2 (4) GB | ? |
FAT32/FAT32X | 8.3 (255 UCS-2 characters with LFN)[i] | SFN: OEM A-Z, 0-9, ! # $ % & ' ( ) - @ ^ _ ` { } ~, 0x80-0xFF, 0x20. LFN: Unicode except NUL, " * / : < > ? \ | [c][i][e] | 32,760 Unicode characters with each path component no more than 255 characters[11] | 4 GB[11] | 512 MB to 16 TB[k] | ? |
FATX | 42 bytes[i] | ASCII. Unicode not permitted. | No limit defined[f] | 2 GB | 16 MB to 2 GB | ? |
Fossil | ? | ? | ? | ? | ? | ? |
GEMDOS | 8.3 | A-Z, a-z, 0-9 ! @ # $ % ^ & ( ) + - = ~ ` ; ' " , < > | [ ] ( ) _[13] | ? | ? | ? | ? |
APFS | 255 UTF-8 characters | Unicode 9.0 encoded in UTF-8[14] | ? | 8 EB | ? | 263 [15] |
F2FS | 255 bytes | Any byte except NUL, /[e] | No limit defined[f] | 3.94 TB | 16 TB | ? |
MFS | 255 bytes | Any byte except :
|
No path (flat filesystem) | 256 MB | 256 MB | ? |
HFS | 31 bytes | Any byte except :
|
Unlimited | 2 GB | 2 TB | ? |
HPFS | 255 bytes | Any byte except NUL[l] | No limit defined[f] | 2 GB | 2 TB[m] | ? |
NTFS | 255 characters | In Win32 namespace: any UTF-16 code unit (case-insensitive) except /\:*"?<>| as well as NUL
In POSIX namespace: any UTF-16 code unit (case-sensitive) except |
32,767 Unicode characters with each path component (directory or filename) up to 255 characters long[f] | 16 EB[n] | 16 EB[n] | 232 |
ReFS | 255 UTF-16 characters[17] | In Win32 namespace: any UTF-16 code unit (case-insensitive) except /\:*"?<>| as well as NUL
In POSIX namespace: any UTF-16 code unit (case-sensitive) except |
32,767 Unicode characters with each path component (directory or filename) up to 255 characters long[17] | 16 EB[17][19] | 1 YB[17] | ? |
HFS Plus | 255 UTF-16 characters[o] | Any valid Unicode[e][p] | Unlimited | slightly less than 8 EB | slightly less than 8 EB[20][21] | ? |
FFS | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 4 GB | 256 TB | ? |
HAMMER | 255 bytes[22] | Any byte except NUL[e] | ? | ? | 1 EB[23] | ? |
UFS1 | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 16 GB to 256 TB | 16 EB | Subdirectory per directory is 32,767[24] |
UFS2 | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 512 GB to 32 PB | 512 ZB[25] (279 bytes) | Subdirectory per directory is 32,767[24] |
ext | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 2 GB | 2 GB | ? |
Xiafs | 248 bytes | Any byte except NUL[e] | No limit defined[f] | 64 MB | 2 GB | ? |
ext2 | 255 bytes | Any byte except NUL, /[e] | No limit defined[f] | 16 GB to 2 TB[d] | 2 TB to 32 TB | ? |
ext3 | 255 bytes | Any byte except NUL, /[e] | No limit defined[f] | 16 GB to 2 TB[d] | 2 TB to 32 TB | ? |
ext4 | 255 bytes[26] | Any byte except NUL, /[e] | No limit defined[f] | 16 GB to 16 TB[d][27] | 1 EB | 232 (static inode limit specified at creation) |
NOVA | 255 bytes | Any byte except NUL, /[e] | No limit defined[f] | 16 EB | 16 EB | ? |
Lustre | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 16 EB on ZFS | 16 EB | ? |
GPFS | 255 UTF-8 codepoints | Any byte except NUL[e] | No limit defined[f] | No limit found | 299 bytes (2 PB tested) | ? |
GFS | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 2 TB to 8 EB[q] | 2 TB to 8 EB[q] | ? |
NILFS | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 8 EB | 8 EB | ? |
ReiserFS | 4,032 bytes/255 characters | Any byte except NUL or '/' [e]
|
No limit defined[f] | 8 TB[r] (v3.6), 4 GB (v3.5) | 16 TB | ? |
Reiser4 | 3,976 bytes | Any byte except / and NUL
|
No limit defined[f] | 8 TB on x86 | ? | ? |
OCFS | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 8 TB | 8 TB | ? |
OCFS2 | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 4 PB | 4 PB | ? |
XFS | 255 bytes[s] | Any byte except NUL[e] | No limit defined[f] | 8 EB[t] | 8 EB[t] | ? |
JFS1 | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 8 EB | 512 TB to 4 PB | ? |
JFS | 255 bytes | Any Unicode except NUL | No limit defined[f] | 4 PB | 32 PB | ? |
QFS | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 16 EB[u] | 4 PB[u] | ? |
BFS | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 12,288 bytes to 260 GB[v] | 256 PB to 2 EB | Unlimited |
AdvFS | 255 characters | Any byte except NUL[e] | No limit defined[f] | 16 TB | 16 TB | ? |
NSS | 256 characters | Depends on namespace used[w] | Only limited by client | 8 TB | 8 TB | ? |
NWFS | 80 bytes[x] | Depends on namespace used[w] | No limit defined[f] | 4 GB | 1 TB | ? |
ODS-5 | 236 bytes[y] | ? | 4,096 bytes[z] | 1 TB | 1 TB | ? |
VxFS | 255 bytes | Any byte except NUL[e] | No limit defined[f] | 16 EB | ? | ? |
UDF | 255 bytes | Any Unicode except NUL | 1,023 bytes[aa] | 16 EB | 512 MB to 16 TB | ? |
ZFS | 255 bytes | Any Unicode except NUL | No limit defined[f] | 16 EB | 256x2^50 ZB (2128 bytes) | 2128 |
Btrfs | 255 bytes | Any byte except '/' and NUL | No limit defined | 16 EB | 16 EB | 264 |
Minix V1 FS | 14 or 30 bytes, set at filesystem creation time | Any byte except NUL[e] | No limit defined[f] | 256.5 MB [ab] | 64 MB | ? |
Minix V2 FS | 14 or 30 bytes, set at filesystem creation time | Any byte except NUL[e] | No limit defined[f] | 2 GB [ab] | 1 GB | ? |
Minix V3 FS | 60 bytes | Any byte except NUL[e] | No limit defined[f] | 2 GB | 4 GB | ? |
VMFS2 | 128 | Any byte except NUL or / [e]
|
2,048 | 4 TB[ac] | 64 TB | ? |
VMFS3 | 128 | Any byte except NUL or / [e]
|
2,048 | 2 TB[ac] | 64 TB | ? |
ISO 9660:1988 | Level 1: 8.3, Level 2 & 3: ~ 180 |
Depends on Level[ad] | ~ 180 bytes? | 4 GB (Level 1 & 2) to 8 TB (Level 3)[ae] | 8 TB[af] | ? |
Joliet ("CDFS") | 64 Unicode characters | All UCS-2 code except *, /, \, :, ;, and ?[29] | ? | same as ISO 9660:1988 | same as ISO 9660:1988 | ? |
Rock Ridge | 255 bytes | Any byte except NUL or /[e] | No limit defined[f] | same as ISO 9660:1988 | same as ISO 9660:1988 | ? |
UniFS | No limit defined (depends on client) | ? | No limit defined (depends on client) | Available cache space at time of write (depends on platform) | No limit defined | No limit defined |
ISO 9660:1999 | ? | ? | ? | ? | ? | ? |
High Sierra Format | ? | ? | ? | ? | ? | ? |
SquashFS | 256 bytes | ? | No limit defined | 16 EB | 16 EB | ? |
BlueStore/Cephfs | ? | any byte, except null, "/" | No limit defined | Max. 264 bytes, 1TB by default [30] | Not limited | Not limited, default is 100,000 files per directory [31] |
File system | Maximum filename length | Allowable characters in directory entries[c] | Maximum pathname length | Maximum file size | Maximum volume size[d] | Max number of files |
Metadata[edit]
File system | 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 | Extended attributes/ Alternate data streams/ forks | Metadata checksum/ ECC |
---|---|---|---|---|---|---|---|---|---|---|
BeeGFS | Yes | Yes | No | Yes | Yes | No | Yes | ? | Yes | Yes |
CP/M file system | No | No | Yes[ag] | No | No | No | No | No | No | No |
DECtape[32] | No | No | Yes | No | No | No | No | No | No | No |
Elektronika BK tape format | No | No | No | No | No | No | No | No | No | Yes |
Level-D | Yes | Yes | Yes | Yes (date only) | Yes | Yes | Yes (FILDAE) | No | No | No |
RT-11[33] | No | No | Yes (date only) | No | No | No | No | No | No | Yes |
Version 6 Unix file system (V6FS)[34] | Yes | Yes | No | Yes | No | No | No | No | No | No |
Version 7 Unix file system (V7FS)[35] | Yes | Yes | No | Yes | No | No | No | No | No | No |
exFAT | No | No | Yes | Yes | No | No | No | No | No | No |
FAT12/FAT16/FAT32 | No | No | Yes | Yes | No[ah] | No | No | No | No[ai] | No |
HPFS | Yes[aj] | No | Yes | Yes | No | No | No | ? | Yes | No |
NTFS | Yes | Yes[ak] | Yes | Yes | Yes | No | Yes | Yes[al] | Yes | No |
ReFS | Yes | Yes | Yes | Yes | Yes | No | Yes | ? | Yes[am] | Yes |
HFS | No | No | Yes | No | No | Yes | No | No | Yes | No |
HFS Plus | Yes | Yes | Yes | Yes | Yes | Yes | Yes | ? | Yes | No |
FFS | Yes | Yes | No | Yes | Yes | No | No | No | No | No |
UFS1 | Yes | Yes | No | Yes | Yes | No | Yes[an] | Yes[an] | No[ao] | No |
UFS2 | Yes | Yes | Yes | Yes | Yes | No | Yes[an] | Yes[an] | Yes | Partial |
HAMMER | Yes | Yes | Yes | Yes | Yes | ? | Yes | Yes | No | Yes |
LFS | Yes | Yes | No | Yes | Yes | No | No | No | No | No |
ext | Yes | Yes | No | No | No | No | No | No | No | No |
Xiafs | Yes | Yes | No | Yes | Yes | No | No | No | No | No |
ext2 | Yes | Yes | No | Yes | Yes | No | Yes[ap] | Yes[ap] | Yes | No |
ext3 | Yes | Yes | No | Yes | Yes | No | Yes[ap] | Yes[ap] | Yes | No |
ext4 | Yes | Yes | Yes | Yes | Yes | No | Yes[ap] | Yes[ap] | Yes | Partial[aq] |
NOVA | Yes | Yes | Yes | Yes | Yes | No | No | No | No | Yes |
Lustre | Yes | Yes | No | Yes | Yes | No | Yes | Yes | Yes | No |
F2FS | Yes | Yes | Yes | Yes | Yes | No | Yes[ap] | Yes[ap] | Yes | No |
GPFS | Yes | Yes | Yes | Yes | Yes | No | Yes | Yes | Yes | Yes |
GFS | Yes | Yes | No | Yes | Yes | No | Yes[ap] | Yes[ap] | Yes | No |
NILFS | Yes | Yes | Yes | No | Yes | No | No | No | No | Yes |
ReiserFS | Yes | Yes | No | Yes | Yes | No | Yes[ap] | Yes[ap] | Yes | No |
Reiser4 | Yes | Yes | No | Yes | Yes | No | No | No | No | No |
OCFS | No | Yes | No | No | Yes | Yes | No | No | No | No |
OCFS2 | Yes | Yes | No | Yes | Yes | No | No | No | No | No |
XFS | Yes | Yes | Partial[ar] | Yes | Yes | No | Yes | Yes[ap] | Yes | Yes |
JFS | Yes | Yes | Yes | Yes | Yes | No | Yes | Yes | Yes | No |
QFS | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes | No |
BFS | Yes | Yes | Yes | No | No | No | No | No | Yes | No |
AdvFS | Yes | Yes | No | Yes | Yes | No | Yes | No | Yes | No |
NSS | Yes | Yes | Yes[as] | Yes[as] | Yes | Yes[as] | Yes | ? | Yes[at][au] | No |
NWFS | Yes | ? | Yes[as] | Yes[as] | Yes | Yes[as] | Yes | ? | Yes[at][au] | No |
ODS-5 | Yes | Yes | Yes | ? | ? | Yes | Yes | ? | Yes[av] | No |
APFS | Yes | Yes | Yes | Yes | Yes | Yes | Yes | ? | Yes | Yes |
VxFS | Yes | Yes | Yes | Yes | Yes | No | Yes | ? | Yes[ap] | No |
UDF | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes | Yes |
Fossil | Yes | Yes[aw] | No | Yes | Yes | No | No | No | No | No |
ZFS | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes[ax] | Yes[ay] | Yes |
Btrfs | Yes | Yes | Yes | Yes | Yes | No | Yes | Yes | Yes | Yes |
Minix V1 | Yes | Yes | No | No | No | No | No | No | No | No |
Minix V2 | Yes | Yes | No | Yes | Yes | No | No | No | No | No |
Minix V3 | Yes | Yes | No | Yes | Yes | No | No | No | No | No |
VMFS2 | Yes | Yes | No | Yes | Yes | No | No | No | No | No |
VMFS3 | Yes | Yes | No | Yes | Yes | No | No | No | No | No |
ISO 9660:1988 | No | No | Yes | No | No | No | No | No | No | No |
Rock Ridge | Yes | Yes | No | Yes[az] | Yes | No | No[ba] | No[bb] | No[bb] | No |
Joliet ("CDFS") | No | No | Yes | No | No | No | No | No | No | No |
ISO 9660:1999 | No | No | Yes | No | No | No | No | No | No | No |
High Sierra | No | No | Yes | No | No | No | No | No | No | No |
SquashFS | Yes | Yes | No | No | Yes | No | No | Yes | Yes | No |
BlueStore/Cephfs | Yes | Yes | Yes | Yes | ? | No | Yes | Yes | Yes | Yes |
File system | 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 | Extended attributes/ Alternate data streams/ forks | Metadata checksum/ ECC |
Features[edit]
File capabilities[edit]
File system | Hard links | Symbolic links | Block journaling | Metadata-only journaling | Case-sensitive | Case-preserving | File Change Log | XIP |
---|---|---|---|---|---|---|---|---|
DECtape | No | No | No | No | No | No | No | No |
BeeGFS | Yes | Yes | Yes | Yes | Yes | Yes | No | No |
Level-D | No | No | No | No | No | No | No | No |
RT-11 | No | No | No | No | No | No | No | No |
APFS | Yes | Yes | ? | ? | Partial | Yes | ? | ? |
Version 6 Unix file system (V6FS) | Yes | No | No | No | Yes | Yes | No | No |
Version 7 Unix file system (V7FS) | Yes | No[bc] | No | No | Yes | Yes | No | No |
exFAT | No | No | No | Partial (with TexFAT only) | No | Yes | No | No |
FAT12 | No | No | No | Partial (with TFAT12 only) | No | Partial (with VFAT LFNs only) | No | No |
FAT16 / FAT16B / FAT16X | No | No | No | Partial (with TFAT16 only) | No | Partial (with VFAT LFNs only) | No | No |
FAT32 / FAT32X | No | No | No? | Partial (with TFAT32 only) | No | Partial (with VFAT LFNs only) | No | No |
GFS | Yes | Yes[bd] | Yes | Yes[be] | Yes | Yes | No | No |
HPFS | No | No | No | No | No | Yes | No | No |
NTFS | Yes | Yes[bf] | No[bg] | Yes[bg] (2000) | Yes[bh] | Yes | Yes | ? |
HFS Plus | Yes[40] | Yes | No | Yes[bi] | Partial[bj] | Yes | Yes[bk] | No |
FFS | Yes | Yes | No | No | Yes | Yes | No | No |
UFS1 | Yes | Yes | No | No | Yes | Yes | No | No |
UFS2 | Yes | Yes | No | Yes[bl] [45] [bm] | Yes | Yes | No | ? |
HAMMER | Yes | Yes | Yes | Yes | Yes | Yes | ? | No |
LFS | Yes | Yes | Yes[bn] | No | Yes | Yes | No | No |
ext | Yes | Yes | No | No | Yes | Yes | No | No |
Xiafs | Yes | Yes | No | No | Yes | Yes | No | No |
ext2 | Yes | Yes | No | No | Yes | Yes | No | Yes[bo] |
ext3 | Yes | Yes | Yes (2001) [bp] | Yes (2001) | Yes | Yes | No | Yes |
ext4 | Yes | Yes | Yes[bp] | Yes | Yes, optional [48] | Yes | No | Yes |
NOVA | Yes | Yes | No | Yes | Yes | Yes | No | Yes |
F2FS | Yes | Yes | Yes[bn] | No | Yes | Yes | No | No |
Lustre | Yes | Yes | Yes[bp] | Yes | Yes | Yes | Yes | No |
NILFS | Yes | Yes | Yes[bn] | No | Yes | Yes | No | No |
ReiserFS | Yes | Yes | Yes[bq] | Yes | Yes | Yes | No | ? |
Reiser4 | Yes | Yes | Yes | No | Yes | Yes | No | ? |
OCFS | No | Yes | No | No | Yes | Yes | No | No |
OCFS2 | Yes | Yes | Yes | Yes | Yes | Yes | No | No |
XFS | Yes | Yes | Yes | Yes | Yes[br] | Yes | Yes | ? |
JFS | Yes | Yes | Yes | Yes (1990) | Yes[bs] | Yes | No | ? |
QFS | Yes | Yes | No | Yes | Yes | Yes | No | No |
BFS | Yes | Yes | No | Yes | Yes | Yes | ? | No |
NSS | Yes | Yes | ? | Yes | Yes[bt] | Yes[bt] | Yes[bu] | No |
NWFS | Yes[bv] | Yes[bv] | No | No | Yes[bt] | Yes[bt] | Yes[bu] | No |
ODS-2 | Yes | Yes[bw] | No | Yes | No | No | Yes | No |
ODS-5 | Yes | Yes[bw] | No | Yes | No | Yes | Yes | ? |
UDF | Yes | Yes | Yes[bn] | Yes[bn] | Yes | Yes | No | Yes |
VxFS | Yes | Yes | Yes | No | Yes | Yes | Yes | ? |
Fossil | No | No | No | No | Yes | Yes | Yes | No |
ZFS | Yes | Yes | Yes[bx] | No[bx] | Yes | Yes | No | No |
Btrfs | Yes | Yes | Yes[by] | No | Yes | Yes | ? | ? |
Minix V1 | Yes | Yes | No | No | Yes | Yes | No | No |
Minix V2 | Yes | Yes | No | No | Yes | Yes | No | No |
Minix V3 | Yes | Yes | No | No | Yes | Yes | No | No |
VMFS2 | Yes | Yes | No | Yes | Yes | Yes | No | No |
VMFS3 | Yes | Yes | No | Yes | Yes | Yes | No | No |
ReFS | No | Yes | ? | ? | Yes[bh] | Yes | ? | ? |
ISO 9660 | No | No | No | No | No | No | No | No |
Rock Ridge | Yes | Yes | No | No | Yes | Yes | No | No |
Joliet ("CDFS") | No | No | No | No | No | Yes | No | No |
SquashFS | Yes | Yes | No | No | Yes | Yes | No | No |
BlueStore/Cephfs | Yes | Yes | Yes | Yes | Yes | Yes | No | No |
File system | Hard links | Symbolic links | Block journaling | Metadata-only journaling | Case-sensitive | Case-preserving | File Change Log | XIP |
Block capabilities[edit]
Note that in addition to the below table, block capabilities can be implemented below the file system layer in Linux (LVM, integritysetup, cryptsetup) or Windows (Volume Shadow Copy Service, SECURITY), etc.
File system | Internal snapshotting / branching | encryption | deduplication | Data checksum/ ECC | Persistent Cache | Multiple Devices | compression |
---|---|---|---|---|---|---|---|
DECtape | No | No | No | No | No | No | No |
BeeGFS | No | No | Yes | No | No | No | Yes |
Level-D | No | No | No | No | No | No | No |
RT-11 | No | No | No | No | No | No | No |
APFS | Yes | Yes | Yes [50] | No | No | No | Yes |
Version 6 Unix file system (V6FS) | No | No | No | No | No | No | No |
Version 7 Unix file system (V7FS) | No | No | No | No | No | No | No |
exFAT | No | No | No | No | No | No | No |
FAT12 | No | No | No | No | No | No | Partial (only inside of Stacker 3/4 and DriveSpace 3 compressed volumes[51]) |
FAT16 / FAT16B / FAT16X | No | No | No | No | No | No | Partial (only inside of Stacker 3/4 and DriveSpace 3 compressed volumes[51]) |
FAT32 / FAT32X | No | No | No | No | No | No | No |
GFS | No | No | ? | No | No | No | No |
HPFS | ? | No | ? | No | No | No | No |
NTFS | No | Yes | Yes[bz][52] | No | No | No | Yes |
HFS Plus | No | No[ca] | No | No | No | No | No |
FFS | No | No | No | No | No | No | No |
UFS1 | No | No | No | No | No | No | No |
UFS2 | Yes | No | No | No | No | No | No |
HAMMER | Yes | No | Yes | Yes | No | No | No |
LFS | Yes | No | No | No | No | No | No |
ext | No | No | No | No | No | No | No |
Xiafs | No | No | No | No | No | No | No |
ext2 | No | No | No | No | No | No | No |
ext3 | No | No | No | No | No | No | No |
ext4 | No | Yes, experimental [53] | No | No[54] | No | No | No |
NOVA | Yes | No | No | Yes | No | No | No |
F2FS | No | Yes, experimental [55] | No | No | No | No | Yes |
Lustre | No | No | No | No | Yes | Yes | No |
NILFS | Yes, continuous[bn] | No | No | Yes | No | No | No |
ReiserFS | No | No | No | No | No | No | No |
Reiser4 | ? | Yes[cb] | ? | No | No | No | Yes |
OCFS | No | No | No | No | No | No | No |
OCFS2 | No | No | No | No | No | No | No |
XFS | No | No | Yes[56] | No[54] | No | No | No |
JFS | ? | No | ? | No | No | No | only in JFS1 on AIX[57] |
QFS | No | No | No | No | No | No | No |
BFS | No | No | No | No | No | No | No |
NSS | Yes | Yes | ? | No | No | No | Yes |
NWFS | ? | No | ? | No | No | No | Yes |
ODS-2 | Yes | No | No | No | No | No | No |
ODS-5 | Yes | No | No | No | No | No | |
UDF | No | No | No | No | No | No | No |
VxFS | Yes[cc] | No | Yes | No | No | No | No |
Fossil | Yes | No | Yes | No | No | No | Yes |
ZFS | Yes | Yes[cd] | Yes | Yes | Yes | Yes | Yes |
Btrfs | Yes | No | Yes | Yes[ce] | No | Yes | Yes |
Minix V1 | No | No | No | No | No | No | No |
Minix V2 | No | No | No | No | No | No | No |
Minix V3 | No | No | No | No | No | No | No |
VMFS2 | No | No | No | No | No | No | No |
VMFS3 | No | No | No | No | No | No | No |
ReFS | ? | No | Yes | Yes[cf] | No | No | No |
ISO 9660 | No | No | No[cg] | No | No | No | No |
Rock Ridge | No | No | No[cg] | No | No | No | No |
Joliet ("CDFS") | No | No | No[cg] | No | No | No | No |
SquashFS | No | No | Yes | Yes | No | No | Yes |
BlueStore/Cephfs | Yes | No | No | Yes | Yes | Yes | Yes |
File system | Internal snapshotting / branching | Filesystem-level encryption | Data deduplication | Data checksum/ ECC | Persistent Cache | Multiple Devices | compression |
Resize capabilities[edit]
File system | Host OS | Offline grow | Online grow | Offline shrink | Online shrink | add and remove physical volumes |
---|---|---|---|---|---|---|
FAT16 / FAT16B / FAT16X | misc. | Yes[61] | No | Yes[61] | No | No |
FAT32 / FAT32X | misc. | Yes[61] | No | Yes[61] | No | No |
exFAT | misc. | No | No | No | No | No |
NTFS | Windows | Yes | Yes | Yes | Yes | No |
ReFS | Windows | ? | Yes | ? | No | No |
HFS+ | macOS | No | Yes | No | Yes | No |
APFS | macOS | ? | ? | ? | ? | ? |
HFS+ | Linux | No | No | No | No | No |
SquashFS | Linux | No | No | No | No | No |
NOVA | Linux | No | No | No | No | No |
JFS[62] | Linux | Yes | No | No | No | No |
XFS[63] | Linux | No | Yes | No | No | No |
Lustre[64] | Linux | ? | Yes | No | No | Yes |
F2FS[65] | Linux | Yes | No | No | No | No |
NTFS[66] | Linux | Yes | No | Yes | No | No |
ext2[67] | Linux | Yes | No | Yes | No | No |
ext3[67] | Linux | Yes | Yes | Yes | No | No |
ReiserFS[68] | Linux | Yes | Yes | Yes | No | No |
Reiser4[69] | Linux | Yes | Yes | Yes | No | No |
ext4[67] | Linux | Yes | Yes | Yes | No | No |
Btrfs[70] | Linux | Yes | Yes | Yes | Yes | Yes |
NILFS[71] | Linux | No | Yes | No | Yes | No |
ZFS | misc. | No | Yes | No | Partial[72] | Yes |
JFS2 | AIX | ? | Yes | ? | Yes | No |
UFS2[73] | FreeBSD | Yes | Yes (FreeBSD 10.0-RELEASE or later) | No | No | No |
HAMMER | DragonflyBSD | ? | ? | ? | ? | ? |
BlueStore/Cephfs | Linux | No | Yes | No | Yes | Yes |
Allocation and layout policies[edit]
File system | Sparse files | Block suballocation | Tail packing | Extents | Variable file block size[ch] | Allocate-on-flush | Copy on write | Trim support |
---|---|---|---|---|---|---|---|---|
DECtape | No | No | No | No | No | No | No | No |
BeeGFS | Yes | No | No | Yes | Yes | Yes | Yes | ? |
Level-D | No | No | No | Yes | No | No | No | ? |
APFS | Yes | ? | ? | Yes | ? | Yes | Yes | Yes[74][75] |
Version 6 Unix file system (V6FS) | Yes | No | No | No | No | No | ? | No |
Version 7 Unix file system (V7FS) | Yes | No | No | No | No | No | ? | No |
exFAT | No | No | No | Partial (only if the file fits into one contiguous block range) | No | No | No | Yes (Linux) |
FAT12 | Partial (only inside of compressed volumes)[76] | Partial (only inside of Stacker 3/4 and DriveSpace 3 compressed volumes[51]) | No | Partial (only inside of compressed volumes)[77] | No | No | No | Yes (Linux) |
FAT16 / FAT16B / FAT16X | Partial (only inside of compressed volumes)[76] | Partial (only inside of Stacker 3/4 and DriveSpace 3 compressed volumes[51]) | No | Partial (only inside of compressed volumes)[77] | No | No | No | Yes (Linux) |
FAT32 / FAT32X | No | No | No | No | No | No | No | Yes (Linux) |
GFS | Yes | No | Partial[ci] | No | No | No | ? | Yes |
HPFS | No | No | No | Yes | No | No | ? | Yes (Linux) |
NTFS | Yes | Partial | No | Yes | No | No | ? | Yes (NT 6.1+; Linux) |
HFS Plus | No | No | No | Yes | No | No | ? | Yes (macOS) |
FFS | Yes | 8:1[cj] | No | No | No | No | ? | No |
UFS1 | Yes | 8:1[cj] | No | No | No | No | ? | No |
UFS2 | Yes | 8:1[cj] | No | No | Yes | No | ? | Yes[78][79] |
LFS | Yes | 8:1[cj] | No | No | No | No | Yes | ? |
ext | Yes | No | No | No | No | No | No | No |
Xiafs | Yes | No | No | No | No | No | ? | ? |
ext2 | Yes | No[ck] | No | No | No | No | No | Yes |
ext3 | Yes | No[ck] | No | No | No | No | No | Yes |
ext4 | Yes | No[ck] | No | Yes | No | Yes | No | Yes |
NOVA | Yes | No | No | Yes | No | No | Yes | ? |
F2FS | Yes | No | No | Partial[cl] | No | Yes | Yes | Yes[80] |
Lustre | Yes | No | No | Yes | No | Yes | ? | ? |
NILFS | Yes | No | No | No | No | Yes | Yes | Yes (Linux NILFS2) |
ReiserFS | Yes | Yes[cm] | Yes | No | No | No | ? | ? |
Reiser4 | Yes | Yes[cm] | Yes | Yes[cn] | No | Yes | ? | Testing[81] |
OCFS | ? | No | No | Yes | No | No | ? | ? |
OCFS2 | Yes | No | No | Yes | No | No | ? | Yes (Linux) |
XFS | Yes | No | No | Yes | No | Yes | Yes, on request[82] | Yes (Linux) |
JFS | Yes | Yes | No | Yes | No | No | ? | Yes (Linux) |
QFS | ? | Yes | No | No | No | No | ? | ? |
BFS | ? | No | No | Yes | No | No | ? | Yes (Haiku) |
NSS | ? | No | No | Yes | No | Yes | ? | ? |
NWFS | ? | Yes[co] | No | No | No | No | ? | ? |
ODS-5 | ? | No | No | Yes | No | No | ? | ? |
VxFS | Yes | ? | No | Yes | No | No | ? | ? |
UDF | Yes | No | No | Yes | No | ?[cp] | Yes, for write once read many media | No |
Fossil | ? | No | No | No | No | No | ? | ? |
ZFS | Yes | Yes | No | No | Yes | Yes | Yes | Yes |
Btrfs | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
VMFS2 | Yes | Yes | No | No | No | No | ? | ? |
VMFS3 | Yes | Yes | No | No | No | No | ? | ? |
ReFS | Yes | ? | ? | ? | No | ? | Yes | Yes (NT 6.1+) |
ISO 9660 | No | No | No | Yes[cq] | No | No | No | No |
Rock Ridge | No | No | No | Yes[cq] | No | No | No | No |
Joliet ("CDFS") | No | No | No | Yes[cq] | No | No | No | No |
SquashFS | Yes | No | Yes | No | No | No | No | No |
BlueStore/Cephfs | Yes | ? | ? | ? | ? | No | Yes | Yes |
File system | Sparse files | Block suballocation | Tail packing | Extents | Variable file block size[ch] | Allocate-on-flush | Copy on write | Trim support |
OS support[edit]
File system | DOS | Linux | macOS | Windows 9x | Windows NT | "classic" Mac OS | FreeBSD | OS/2 | BeOS | Minix | Solaris | z/OS |
---|---|---|---|---|---|---|---|---|---|---|---|---|
APFS | No | Partial (read-only with apfs-fuse[83] or linux-apfs[84]) | Yes (Since macOS Sierra) |
No | No | No | No | No | No | No | No | No |
BeeGFS | No | Yes | ? | No | No | No | No | No | ? | ? | ? | No |
DECtape | No | No | No | No | No | No | No | No | No | No | No | No |
Level-D | No | ? | ? | No | No | No | No | No | No | No | ? | ? |
RT-11 | No | No | No | No | No | No | No | No | No | No | No | No |
Version 6 Unix file system (V6FS) | No | ? | No | No | No | No | No | No | No | No | No | No |
Version 7 Unix file system (V7FS) | No | Yes | ? | No | No | No | No | No | ? | ? | ? | ? |
exFAT | No | Yes (since 5.4,[85] available as a kernel module or FUSE driver for earlier versions) | Yes | No | Yes (installable drivers for Windows XP, 2003. Included with Windows Vista SP1 and newer.) | No | Yes (available as a FUSE driver) | No | No | No | Yes (available as a FUSE driver) | No |
FAT12 | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Partial (via dosdir, dosread, doswrite) | Yes | ? |
FAT16 / FAT16B / FAT16X | Yes (FAT16 from DOS 3.0, FAT16B from DOS 3.31, FAT16X from DOS 7.0) | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Partial (via dosdir, dosread, doswrite, not FAT16X) | Yes | ? |
FAT32 / FAT32X | Yes (from DOS 7.10) | Yes | Yes | Yes (from Windows 95 OSR2) | Yes (from Windows 2000) | Yes? | Yes | Yes | Yes | No | Yes | ? |
GFS | No | Yes | ? | No | No | No | No | ? | ? | ? | ? | ? |
HPFS | Partial (with third-party drivers) | Yes | ? | No | Partial (with NT 3.1 to 4.0 only) | ? | Yes | Yes (from OS/2 1.2) | ? | No | ? | ? |
NTFS | Partial (with third-party drivers) | Yes with the Paragon NTFS kernel driver or ntfs-3g | Yes natively read only, write support with Paragon NTFS or ntfs-3g | Yes (with 3rd-party drivers like Paragon NTFS for Win98, DiskInternals NTFS Reader) | Yes | No | Yes with ntfs-3g | ? | Yes with ntfs-3g | No | Yes with ntfs-3g | ? |
Apple HFS | No | Yes | No write support since Mac OS X 10.6 and no support at all since macOS 10.15 | No | Yes with Paragon HFS+ [86] | Yes | No | ? | Yes | No | ? | No |
Apple HFS Plus | No | Partial - writing support only to unjournalled FS | Yes | No | Yes with Paragon HFS+ [86] | Yes from Mac OS 8.1 | No | ? | with addon | No | ? | No |
FFS | No | ? | Yes | No | ? | ? | Yes | ? | ? | ? | ? | ? |
UFS1 | No | Partial - read only | Yes | No | Partial (with ufs2tools, read only) | ? | Yes | No | ? | ? | Yes | ? |
UFS2 | No | Yes | Yes | No | Partial (with ufs2tools, read only) | ? | Yes | No | ? | ? | ? | ? |
LFS | No | ? | ? | No | No | ? | No | No | ? | ? | ? | ? |
ext | No | Yes - until 2.1.20 | No | No | No | No | No | No | No | No | No | No |
Xiafs | No | Yes - until 2.1.20 |
No | No | No | No | No | No | No | No | No | No |
ext2 | No | Yes | Yes with Paragon ExtFS [89] or ext2fsx | Partial (read-only, with explore2fs)[90] | Yes with Paragon ExtFS [91] or partial with Ext2 IFS[92] or ext2fsd[93] | No | Yes | No | Yes | ? | ? | ? |
ext3 | No | Yes | Yes with Paragon ExtFS [89] or partial with ext2fsx (journal not updated on writing) | Partial (read-only, with explore2fs)[90] | Yes with Paragon ExtFS [91] or partial with Ext2 IFS[92] or ext2fsd[93] | Partial (read only)[citation needed] | Yes[94] | No | with addon | ? | Yes | ? |
ext4 | No | Yes | Yes with Paragon ExtFS [89] | No | Yes with Paragon ExtFS [91] or partial with Ext2 IFS[92] or ext2fsd[93] | ? | Yes since FreeBSD 12.0[94] | No | with addon | ? | ? | ? |
NOVA | No | Yes | No | No | No | No | No | No | No | No | No | No |
Lustre | No | Yes[95] | ? | No | No | ? | No | ? | ? | ? | Yes | ? |
NILFS | No | Yes as an external kernel module | ? | No | ? | ? | No | ? | ? | ? | ? | ? |
F2FS | No | Yes | No | No | No | No | No | No | No | No | No | No |
ReiserFS | No | Yes | ? | No | No | ? | Partial - Read Only from 6.0 to 10.x[96] and dropped in 11.0[97][98] | ? | with addon | ? | ? | ? |
Reiser4 | No | Yes with a kernel patch | ? | No | No | ? | No | ? | ? | ? | ? | ? |
SpadFS | No | Yes | No | No | No | No | ? | No | No | No | No | No |
OCFS | No | Yes | ? | No | No | ? | No | No | ? | ? | ? | ? |
OCFS2 | No | Yes | ? | No | No | ? | No | No | ? | ? | ? | ? |
XFS | No | Yes | ? | No | No | ? | Partial | ? | with addon (read only) | ? | ? | ? |
JFS | No | Yes | ? | No | No | ? | No | Yes | ? | ? | ? | ? |
QFS | No | Partial - client only[99] | ? | No | No | ? | No | No | ? | ? | Yes | ? |
Be File System | No | Partial - read-only | ? | No | No | ? | No | No | Yes | ? | ? | ? |
NSS | No | Yes via EVMS[cr] | ? | No | No | ? | No | No | ? | ? | ? | ? |
NWFS | Partial (with Novell drivers) | ? | ? | No | No | ? | Yes | No | ? | ? | ? | ? |
ODS-2 | No | ? | ? | No | No | ? | No | No | ? | ? | ? | ? |
ODS-5 | No | ? | ? | No | No | ? | No | No | ? | ? | ? | ? |
UDF | No | Yes | Yes | ? | Yes | ? | Yes | ? | ? | ? | Yes | ? |
VxFS | No | Yes | ? | No | No | ? | No | No | ? | ? | Yes | ? |
Fossil | No | Yes[cs] | Yes[cs] | No | No | No | Yes[cs] | No | No | No | Yes[cs] | ? |
ZFS | No | Yes with FUSE[100] or as an external kernel module[101] | Yes with Read/Write Developer Preview[102] | No | Yes[103] | No | Yes | No | No | No | Yes | No |
Btrfs | No | Yes | ? | No | Yes with WinBtrfs[104] | ? | ? | ? | ? | ? | ? | ? |
VMFS2 | No | ? | ? | No | No | ? | No | No | ? | ? | ? | ? |
VMFS3 | No | ? | ? | No | No | ? | No | No | ? | ? | ? | ? |
IBM HFS | No | No | No | No | No | No | No | No | No | No | No | Yes |
IBM zFS | No | No | No | No | No | No | No | No | No | No | No | Yes |
ReFS | No | Partial - with Paragon ReFS for Linux | ? | No | Yes (from Windows Server 2012 and from Windows 8.1) | ? | ? | ? | ? | ? | ? | ? |
ISO 9660 | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Rock Ridge | No | Yes | Yes | No | No | No | Yes | No | No | Yes | Yes | ? |
Joliet ("CDFS") | No | Yes | Yes | Yes | Yes | ? | Yes | Yes | Yes | ? | Yes | ? |
SquashFS | No | Yes | Partial (There are ports of unsquashfs and mksquashfs.) | No | Partial (There are ports of unsquashfs and mksquashfs.) | No | Partial (There are ports of unsquashfs and mksquashfs and fusefs-port.[105][106]) | No | No | No | No | No |
BlueStore/Cephfs | No | Yes | No[ct] | No | No[cu] | No | No[ct] | No | No | No | No | No |
File system | DOS | Linux | macOS | Windows 9x | Windows NT | "classic" Mac OS | FreeBSD | OS/2 | BeOS | Minix | Solaris | z/OS |
See also[edit]
- List of file systems
- List of file archivers
- Comparison of file archivers
- List of archive formats
- Comparison of archive formats
Notes[edit]
- ^ IBM introduced JFS with the initial release of AIX Version 3.1 in 1990. This file system now called JFS1. The new JFS, on which the Linux port was based, was first shipped in OS/2 Warp Server for e-Business in 1999. The same sourcebase was also used for release JFS2 on AIX 5L.
- ^ Microsoft first introduced FAT32 in MS-DOS 7.1 / 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.
- ^ a b c d e 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; operating systems may also place restrictions of their own, across all filesystems. DOS, Windows, and OS/2 allow only the following characters from the current 8-bit OEM codepage in SFNs: A-Z, 0-9, characters ! # $ % & ' ( ) - @ ^ _ ` { } ~, as well as 0x80-0xFF and 0x20 (SPACE). Specifically, lowercase letters a-z, characters " * / : < > ? \ | + , . ; = [ ], control codes 0x00-0x1F, 0x7F and in some cases also 0xE5 are not allowed.) In LFNs, any UCS-2 Unicode except \ / : ? * " > < | and NUL are allowed in file and directory names across all filesystems. Unix-like systems disallow the characters / and NUL in file and directory names across all filesystems.
- ^ a b c d e 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).
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak 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.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am The on-disk structures have no inherent limit. Particular Installable File System drivers and operating systems may impose limits of their own, however. Limited by its Current Directory Structure (CDS), DOS does not support more than 32 directory levels (except for DR DOS 3.31-6.0) or full pathnames longer than 66 bytes for FAT, or 255 characters for LFNs. Windows NT does not support full pathnames longer than 32,767 bytes for NTFS. Older POSIX APIs which rely on the
PATH_MAX
constant have a limit of 4,096 bytes on Linux but this can be worked around. Linux itself has no hard path length limits.[9][10] - ^ The file size in the inode is 1 8-bit byte followed by 1 16-bit word, for 24 bits. The actual maximum was 8,847,360 bytes, with 7 singly-indirect blocks and 1 doubly-indirect block; PWB/UNIX 1.0's variant had 8 singly-indirect blocks, making the maximum 524,288 bytes or half a MB.
- ^ 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.
- ^ a b c d e f Depends on whether the FAT12, FAT16, and FAT32 implementation has support for LFNs. Where it does not, as in OS/2, 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 OEM characters (space padded in both the basename and extension parts) and may not contain NUL (end-of-directory marker) or character 5 (replacement for character 229 which itself is used as deleted-file marker). Short names also must not contain lowercase letters. A few special device names (CON, NUL, AUX, PRN, LPT1, COM1, etc.) should be avoided, as some operating systems (notably DOS, OS/2 and Windows) reserve them.
- ^ a b On-disk structures would support up to 4 GB, but practical file size is limited by volume size.
- ^ 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.[12]
- ^ 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.
- ^ a b 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; in Windows 10 version 1709, the limit is 8 PB when using 2 MB cluster size.
- ^ The "classic" 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.
- ^ a b 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.
- ^ ReiserFS has a theoretical maximum file size of 1 EB, but "page cache limits this to 8 Ti on architectures with 32 bit int"[28]
- ^ Note that the filename can be much longer XFS#Extended attributes
- ^ a b 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.
- ^ a b 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.
- ^ Varies wildly according to block size and fragmentation of block allocation groups.
- ^ a b NSS allows files to have multiple names, in separate namespaces.
- ^ 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.
- ^ This restriction might be lifted in newer versions.
- ^ a b Sparse files can be larger than the file system size, even though they can't contain more data.
- ^ a b 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.
- ^ 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 GB (or 4 GB depending on implementation) 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.
- ^ Implemented in later versions as an extension
- ^ 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.
- ^ The f-node contains a field for a user identifier. This is not used except by OS/2 Warp Server, however.
- ^ 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.[36]
- ^ Initially, ReFS lacked support for ADS, but Server 2012 R2 and up add support for ADS on ReFS
- ^ a b c d 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).
- ^ a b c d e f g h i j k l m n 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.
- ^ Metadata is mostly checksummed,[37] however Direct/indirect/triple-indirect block maps are not protected by checksums[38]
- ^ Creation time stored since June 2015, xfsprogs version 3.2.3
- ^ a b c d e f The local time, time zone/UTC offset, and date are derived from the time settings of the reference/single timesync source in the NDS tree.
- ^ a b 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.
- ^ a b 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.
- ^ Record Management Services (RMS) attributes include record type and size, among many others.
- ^ 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.
- ^ Supported on FreeBSD and Linux implementations, support may not be available on all operating systems.
- ^ Solaris "extended attributes" are really full-blown alternate data streams, in both the Solaris UFS and ZFS.
- ^ Access times are preserved from the original file system at creation time, but Rock Ridge file systems themselves are read-only.
- ^ libburnia can back up and restore ACLs with file system creation and extraction programs, but no kernel support exists.
- ^ a b libburnia can back up and restore extended attributes and MAC labels with file system creation and extraction programs, but no kernel support exists.
- ^ 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.
- ^ 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
- ^ As of Windows Vista, NTFS fully supports symbolic links.[39] NTFS 3.0 (Windows 2000) and higher can create junctions, which allow entire directories (but not individual files) to be mapped to elsewhere in the directory tree of the same partition (file system). These are implemented through reparse points, which allow the normal process of filename resolution to be extended in a flexible manner.
- ^ a b NTFS stores everything, even the file data, as meta-data, so its log is closer to block journaling.
- ^ a b 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.
- ^ Metadata-only journaling was introduced in the Mac OS X 10.2.2 HFS Plus driver; journaling is enabled by default on Mac OS X 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 X 10.3 on the command newfs_hfs -s will create a case-sensitive new file system.[41] 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.[42][43]
- ^ Mac OS X 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).[44]
- ^ "Soft dependencies" (softdep) in NetBSD, called "soft updates" in FreeBSD provide meta-data consistency at all times without double writes (journaling)
- ^ Journaled Soft Updates (SU+J) are the default as of FreeBSD 9.x-RELEASE [46][47]
- ^ a b c d e f UDF, LFS, and NILFS are log-structured file systems and behave as if the entire file system were a journal.
- ^ Linux kernel versions 2.6.12 and newer.
- ^ a b c Off by default.
- ^ Full block journaling for ReiserFS was added to Linux 2.6.8.
- ^ Optionally no on IRIX and Linux.
- ^ 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.
- ^ a b c d 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.
- ^ a b 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.[49]
- ^ a b Available only in the "NFS" namespace.
- ^ a b These are referred to as "aliases".
- ^ a b 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.
- ^ Btrfs is a transactional filesystem using copy-on-write semantics, guaranteeing an always-consistent on-disk state without the use of a traditional journal. It keeps track of last five transactions and uses checksums to find problematic drives, making write intent logs unnecessary.
- ^ Supported only on Windows Server SKUs. However, partitions deduplicated on Server can be used on Client.
- ^ HFS+ does not actually encrypt files: to implement FileVault, OS X creates an HFS+ filesystem in a sparse, encrypted disk image that is automatically mounted over the home directory when the user logs in.
- ^ Reiser4 supports transparent compression and encryption with the cryptcompress plugin which is the default file handler in version 4.1.
- ^ VxFS provides an optional feature called "Storage Checkpoints" which allows for advanced file system snapshots.
- ^ Applies to proprietary ZFS release 30 and ZFS On Linux. Encryption support is not yet available in all OpenZFS ports.[58][59][60]
- ^ disabling copy-on-write (COW) to prevent fragmentation also disables data checksumming
- ^ By using the per-file "integrity stream" that internally stores a checksum per cluster. Those per cluster checksums are not accessible so it is actually a per file feature and not a per block feature. Integrity streams are not enabled by default.
- ^ a b c Some file system creation implementations reuse block references and support deduplication this way. This is not supported by the standard, but usually works well due to the file system's read-only nature.
- ^ a b 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.
- ^ Only for "stuffed" inodes
- ^ a b c d Other block:fragment size ratios supported; 8:1 is typical and recommended by most implementations.
- ^ a b c Fragments were planned, but never actually implemented on ext2 and ext3.
- ^ Stores one largest extent in disk, and caches multiple extents in DRAM dynamically.
- ^ a b Tail packing is technically a special case of block suballocation where the suballocation unit size is always 1 byte.
- ^ In "extents" mode.
- ^ 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.
- ^ Depends on UDF implementation.
- ^ a b c ISO 9660 Level 3 only
- ^ Supported using only EVMS; not currently supported using LVM
- ^ a b c d Provided in Plan 9 from User Space
- ^ a b FUSE based driver available that can eliminate need for iSCSI gateways or SMB shares, but the physical backend store BlueStore only runs on Linux.
- ^ Filesystem driver "Dokany" available that can eliminate need for iSCSI gateways or SMB shares, but the physical backend store BlueStore only runs on Linux.
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