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Ext4

ext4 (fourth extended filesystem) is a journaling file system for Linux, developed as the successor to ext3.

Geography, Features & Limitations

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Explore the main themes, entities and connections around Ext4. Start with the topic map, then use the sections below for research and deeper semantic analysis.

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Features

35 related topics

Limitations

6 related topics

Delayed allocation and potential data loss

4 related topics

Interoperability

4 related topics

Key facts & relationships

High-confidence facts extracted from structured source data. Use them as anchors for further research.

Allowed filename characters
All characters and character sequences permitted, except for NULL ('\0'), '/', and the special file names "." and ".." which are reserved for indicating (respectively) current a…
Attributes
acl, bh, bsddf, commit=nrsec, data=journal, data=ordered, data=writeback, delalloc, extents, journal_dev, mballoc, minixdf, noacl, nobh, nodelalloc, noextents, nomballoc, nombca…
Bad blocks
Table
Copy-on-write
No
Data deduplication
No
Date range
14 December 1901 – 10 May 2446

Topics to explore

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Overview

Adoption

Features

Limitations

Delayed allocation and potential data loss

Implementation

  • Read Read (system call)
  • Write Write (system call)
  • Lseek Lseek (system call)?action=edit&redlink=1

Interoperability

General Architecture

Advanced semantic analysis

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Map overview Semantic statistics

Ext4

Nodes77
Edges76
Triples91
Avg. degree1.97
Density0.025974
Components1

How this topic connects Entity context

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Ext4

Top relations

related to External links · 25
Ext4 → Archived, CROSSMETAExt2read, December, Ext2/3 Filesystem, Ext2/Ext3, Ext2Fsd Open, FS, FUSE, June, Kernel Log, Linux, LVM2, MacFuse, March, October, Open, Ottawa Linux Symposium, Supports Mac OS, The, The Next Generation
related to Limitations · 10
Ext4 → Btrfs, Google, However, Huawei, IBM, In, SuSE, The, Theodore Ts'o, Ts'o
related to Interoperability · 9
Ext4 → Although, ARM64, Insider Preview Build, It, Linux, Specifically, Windows, Windows Subsystem, WSL
Supported operating systems · 5
Ext4 → FreeBSD (full read/write support since version 12.0), KolibriOS (read-only), Linux, macOS (read-only with ext4fuse, full with ExtFS), Windows (read–write without journaling with ext2fsd)
related to Delayed allocation and potential data loss · 5
Ext4 → Because, Due, The, There, Unix
related to General Architecture · 4
Ext4 → Blocks, By, KiB, The
related to Adoption · 3
Ext4 → Debian, Linux, Ubuntu
related to Flexible block groups · 2
Ext4 → Block, In
Allowed filename characters · 1
Ext4 → All characters and character sequences permitted, except for NULL ('\0'), '/', and the special file names "." and ".." which are reserved for indicating (respectively) current a…
Attributes · 1
Ext4 → acl, bh, bsddf, commit=nrsec, data=journal, data=ordered, data=writeback, delalloc, extents, journal_dev, mballoc, minixdf, noacl, nobh, nodelalloc, noextents, nomballoc, nombca…

Important terminology Word statistics

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Important terminology

file linux ext3 block system filesystem systems bitmap data group windows kernel inode write version new development gpt open disk

Entity relationships Subject–Predicate–Object triples

SubjectPredicateObjectConfidenceSrc
Ext4Allowed filename charactersAll characters and character sequences permitted, except for NULL ('\0'), '/', and the special file names "." and ".." which are reserved for indicating (respectively) current a…1.00infobox
Ext4Attributesacl, bh, bsddf, commit=nrsec, data=journal, data=ordered, data=writeback, delalloc, extents, journal_dev, mballoc, minixdf, noacl, nobh, nodelalloc, noextents, nomballoc, nombca…1.00infobox
Ext4Bad blocksTable1.00infobox
Ext4Copy-on-writeNo1.00infobox
Ext4Data deduplicationNo1.00infobox
Ext4Date range14 December 1901 – 10 May 24461.00infobox
Ext4Date resolutionNanosecond1.00infobox
Ext4Dates recordedModification (mtime), data or attribute modification (ctime), access (atime), deletion (dtime), creation (crtime)1.00infobox
Ext4Developer(s)Mingming Cao, Andreas Dilger, Alex Zhuravlev (Tomas), Dave Kleikamp, Theodore Ts'o, Eric Sandeen, Sam Naghshineh, others1.00infobox
Ext4Directory contentsLinked list, hashed B-tree1.00infobox
Ext4File allocationExtents / Bitmap1.00infobox
Ext4File system permissionsUnix permissions, POSIX ACLs1.00infobox
Ext4ForksNo1.00infobox
Ext4Full nameFourth extended file system1.00infobox
Ext4Introduced10 October 2006 with Linux 2.6.191.00infobox
Ext4Max file size16–256 TiB (for 4–64 KiB block size)1.00infobox
Ext4Max filename length255 bytes (fewer for multibyte character encodings such as Unicode)1.00infobox
Ext4Max no. of files4 billion (specified at filesystem creation time)1.00infobox
Ext4Max volume size1 EiB1.00infobox
Ext4Partition IDs.mw-parser-output .monospaced{font-family:monospace,monospace}0x83: MBR / EBR. EBD0A0A2-B9E5-4433-87C0-68B6B72699C7: GPT Windows BDP. 0FC63DAF-8483-4772-8E79-3D69D8477DE4: GPT L…1.00infobox
Ext4Preceded byext31.00infobox
Ext4Supported operating systemsLinux1.00infobox
Ext4Supported operating systemsFreeBSD (full read/write support since version 12.0)1.00infobox
Ext4Supported operating systemsmacOS (read-only with ext4fuse, full with ExtFS)1.00infobox
Ext4Supported operating systemsWindows (read–write without journaling with ext2fsd)1.00infobox
Ext4Supported operating systemsKolibriOS (read-only)1.00infobox
Ext4Transparent compressionNo1.00infobox
Ext4Transparent encryptionYes1.00infobox

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