Ext4
ext4 (viertes Extended File System) ist ein quelloffenes Dateisystem und die neueste Version der Extended-Reihe von Dateisystemen. Es ist das primäre Dateisystem, das von vielen Linux-Systemen verwendet wird, wodurch es wohl das stabilste und am besten getestete Dateisystem ist, das von Linux unterstützt wird.
Ursprünglich als Fork von ext3 entwickelt, bringt ext4 neue Funktionen, Leistungsverbesserungen und die Aufhebung von Größenbeschränkungen mit moderaten Änderungen am Festplattenformat. Es kann Volumes bis zu 1 EB und mit einer maximalen Dateigröße von 16 TB umfassen. Anstelle der klassischen ext2/3-Bitmap-Blockzuordnung verwendet ext4 Extents, die die Leistung großer Dateien verbessern und die Fragmentierung reduzieren. Ext4 bietet außerdem ausgefeiltere Blockzuweisungsalgorithmen (verzögerte Zuweisung und Multiblockzuweisung), die dem Dateisystemtreiber mehr Möglichkeiten zur Optimierung des Datenlayouts auf der Festplatte bieten.
Installation
Kernel
Aktivieren Sie die folgenden Kerneloptionen für die ext4-Unterstützung:
File systems --->
<*> The Extended 4 (ext4) filesystem
Unterstützung für optionale ext4-Funktionen:
File systems --->
[*] Ext4 POSIX Access Control Lists
[*] Ext4 Security Labels
[ ] EXT4 debugging support
Ext3
A normal ext4 system will not need to enable ext3 or ext2 options. These options are here solely for historical purposes.
Activate the following kernel options for ext3 support:
File systems --->
<*> Ext3 journalling file system support
Support for optional ext3 features:
File systems --->
[*] Default to 'data=ordered' in ext3
[*] Ext3 extended attributes
[*] Ext3 POSIX Access Control Lists
[*] Ext3 Security Labels
Ext2
Ext2 does not have journaling, support for this was added in Ext3
Activate the following kernel options for ext2 support:
File systems --->
<*> Second extended fs support
Support for optional ext2 features:
File systems --->
[*] Ext2 extended attributes
[*] Ext2 POSIX Access Control Lists
[*] Ext2 Security Labels
The original ext3 filesystem code was removed from the Linux Kernel with version 4.3, instead the ext4 filesystem code can now handle ext2, ext3 and ext4 filesystems. It will maintain compatibility if the filesystem is mounted as ext2 or ext3, and will provide upgradability when mounted as ext4. Additionally tune2fs can be used to add ext3- and ext4-specific features to an existing ext2 or ext3 filesystem, though certain hard limits will remain.
The original ext2 filesystem code remains available.
Both ext2 and ext3 file timestamps are affected by the year 2038 problem, while ext4 is Y2k38-safe since 2016, Kernel 4.3.6 and e2fsprogs 1.43.
Unterstützung für große Laufwerke
-*- Enable the block layer --->
[*] Support for large (2TB+) block devices and files
USE-Flags
USE flags for sys-fs/e2fsprogs Standard EXT2/EXT3/EXT4 filesystem utilities
archive
|
Add support for mke2fs to read a tarball as input. This allows not needing privileges. Needs app-arch/libarchive. |
cron
|
Install e2scrub_all cron script |
fuse
|
Build fuse2fs, a FUSE file system client for ext2/ext3/ext4 file systems |
nls
|
Add Native Language Support (using gettext - GNU locale utilities) |
static-libs
|
Build static versions of dynamic libraries as well |
test
|
Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently) |
tools
|
Build extfs tools (mke2fs, e2fsck, tune2fs, etc.) |
Emerge
The sys-fs/e2fsprogs package and should be available as part of the default system set.
root #emerge --ask sys-fs/e2fsprogsBedienung
Erstellung
Der Befehl mkfs.ext4 zerstört unwiderruflich den Inhalt der Partition, die er formatieren soll. Achten Sie darauf, die richtige Partition auszuwählen!
Um ein ext4-Dateisystem auf der Partition /dev/sda1 zu erstellen:
root #mkfs.ext4 /dev/sda1Mounting
See filesystem.
Utilities
Utilities included in the package consist of:
| Utility | Description | Man page |
|---|---|---|
| badblocks | A small program for stress testing block devices. | Man page |
| debugfs | An ext2/ext3/ext4 file system debugger. | Man page |
| dumpe2fs | A tool to dump ext2/ext3/ext4 filesystem information. | Man page |
| e2fsck | A tool for checking ext2/ext3/ext4 filesystems. | Man page |
| e2image | A tool for saving critical ext2/ext3/ext4 filesystem metadata to a file. | Man page |
| e2label | A tool to change the label on an ext2/ext3/ext4 filesystem (symlinks to tune2fs). | |
| e2undo | A tool to replay an undo log for an ext2/ext3/ext4 filesystem. | Man page |
| fsck.ext2 | Checks, specifically, an ext2 filesystem (symlinks to e2fsck). | |
| fsck.ext3 | Checks, specifically, an ext3 filesystem (symlinks to e2fsck). | |
| fsck.ext4 | Checks, specifically, an ext4 filesystem (symlinks to e2fsck). | |
| fsck.ext4dev | Checks, specifically, an ext4dev filesystem (symlinks to e2fsck). | |
| logsave | A tool to save the output of a command in a logfile. | Man page |
| mke2fs | The base program for creating ext2/ext3/ext4 filesystems. Creation commands symlink here. | Man page |
| mkfs.ext2 | Creates, specifically, an ext2 filesystem (symlinks to mke2fs). | |
| mkfs.ext3 | Creates, specifically, an ext3 filesystem (symlinks to mke2fs). | |
| mkfs.ext4 | Creates, specifically, an ext4 filesystem (symlinks to mke2fs). | |
| mkfs.ext4dev | Creates, specifically, an ext24dev filesystem (symlinks to mke2fs). | |
| resize2fs | An ext2/ext3/ext4 filesystem resizer. | Man page |
| tune2fs | Adjust tunable filesystem parameters on ext2/ext3/ext4 filesystems. | Man page |
| Utility | Description | Man page |
|---|---|---|
| chattr | Change file attributes on a Linux filesystem. | Man page |
| lsattr | List file attributes on a Linux second extended filesystem. | Man page |
| Utility | Description | Man page |
|---|---|---|
| e2freefrag | Report free space fragmentation information. | Man page |
| e4defrag | An online defragmenter for ext4 filesystem. | Man page |
| filefrag | Report on file fragmentation. | Man page |
| mklost+found | Create a lost+found directory on a mounted Linux second extended filesystem. | Man page |
Siehe auch
- Ext4 encryption — provides instructions on encrypting files in a home partition using the ext4 filesystem's built-in file based encryption.
- JFS — a 64-bit journaling filesystem created by IBM.
- Btrfs — ein copy-on-write (CoW) Dateisystem für Linux, welches die Implementierung erweiterter Funktionen anstrebt und einen Fokus auf Fehlertoleranz, Selbsheilung und einfache Administration legt.
- XFS — ein leistungsstarkes Journaling-Dateisystem
- F2FS — a filesystem designed for NAND flash-based devices.