Difference between revisions of "Ext4"
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↑ https://lwn.net/Articles/639427/
↑ https://en.wikipedia.org/wiki/Ext4#Features
↑ https://www.thomas-krenn.com/en/wiki/Ext4_Filesystem#Lazy_Initialization
↑ https://manpages.debian.org/stretch/e2fsprogs/resize2fs.8.en.html
↑ https://github.com/tytso/e2fsprogs/commit/bf69235ad0073c80386b70caba0e1b58e5f85697
↑ https://www.technomenace.com/2014/08/how-to-extend-lvm-on-qcow2-images/
↑ https://en.wikipedia.org/wiki/Ext4#Features
↑ https://linux.die.net/man/8/xfs_growfs
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| − | [[wikipedia:ext4|ext4]] journaling [[File system|file system]] or fourth extended filesystem is a [[journaling file system]] for [[Linux]] and it is the default file system for many Linux distributions such as [[Ubuntu]] and [[Debian]]. [[Red Hat Enterprise Linux|RHEL]] default fs is [[XFS]]. | + | {{lc}} |
| + | [[wikipedia:ext4|ext4]] ([[2008]]) [[journaling]] [[File system|file system]] or fourth extended filesystem is a [[journaling file system]] for [[Linux]] and it is the default file system for many Linux distributions such as [[Ubuntu]] and [[Debian]]. [[Red Hat Enterprise Linux|RHEL]] default fs is [[XFS]]. | ||
| − | Since [[Linux kernel]] 4.1 on June 2015<ref>https://lwn.net/Articles/639427/</ref>, ext4 natively supports file [[cryptography|encryption]] | + | Since [[Linux kernel]] [[4.1]] on June 2015<ref>https://lwn.net/Articles/639427/</ref>, ext4 natively supports file [[cryptography|encryption]] |
| + | |||
| + | * https://man7.org/linux/man-pages/man5/ext4.5.html | ||
==Basic commands== | ==Basic commands== | ||
| − | *[[mkfs]] and [[mke2fs]] | + | * <code>[[mkfs]]</code> and <code>[[mke2fs]]</code> |
* Creating an ext4 filesystem: (by default since 2010 will do a quick and lazy initialization <ref>https://en.wikipedia.org/wiki/Ext4#Features</ref>) | * Creating an ext4 filesystem: (by default since 2010 will do a quick and lazy initialization <ref>https://en.wikipedia.org/wiki/Ext4#Features</ref>) | ||
:Creating an ext4 in a disk | :Creating an ext4 in a disk | ||
| − | :: <code>[[mkfs.ext4]] /dev/ | + | :: <code>[[mkfs.ext4]] [[/dev/sd]]X</code> |
:Creating an ext4 FS in an [[Linux Administration/Devices and Filesystems/LVM|LV]]: | :Creating an ext4 FS in an [[Linux Administration/Devices and Filesystems/LVM|LV]]: | ||
:: <code>mkfs.ext4 /dev/vg01/lv01</code> | :: <code>mkfs.ext4 /dev/vg01/lv01</code> | ||
| Line 14: | Line 17: | ||
=== resize2fs === | === resize2fs === | ||
| − | [[resize2fs]]<ref>https://manpages.debian.org/stretch/e2fsprogs/resize2fs.8.en.html</ref> file system resizer for ext2/ext3/[[ext4]] (<code>resize2fs /dev/mapper/VolGroup-lv_root</code>). Online resize (expand) is supported in resize2fs since 2006<ref>https://github.com/tytso/e2fsprogs/commit/bf69235ad0073c80386b70caba0e1b58e5f85697</ref>.<ref>https://www.technomenace.com/2014/08/how-to-extend-lvm-on-qcow2-images/</ref>. resize2fs code: https://github.com/tytso/e2fsprogs/blob/master/resize/resize2fs.c. See also: [[ext2online]] | + | <code>[[resize2fs]]</code><ref>https://manpages.debian.org/stretch/e2fsprogs/resize2fs.8.en.html</ref> file system resizer for ext2/ext3/[[ext4]] (<code>resize2fs /dev/mapper/VolGroup-lv_root</code>). Online resize (expand) is supported in resize2fs since 2006<ref>https://github.com/tytso/e2fsprogs/commit/bf69235ad0073c80386b70caba0e1b58e5f85697</ref>.<ref>https://www.technomenace.com/2014/08/how-to-extend-lvm-on-qcow2-images/</ref>. resize2fs code: https://github.com/tytso/e2fsprogs/blob/master/resize/resize2fs.c. See also: [[ext2online]] |
| − | == | + | == ext4 features timeline== |
| − | * 2015 File encryption | + | * 2020 ext4 [[fast commit]] support ([[Linux Kernel 5.10]] December 2020) |
| + | * [[2015]] [[File encryption]] | ||
* 2010 Lazy Initialization<ref>https://en.wikipedia.org/wiki/Ext4#Features</ref> | * 2010 Lazy Initialization<ref>https://en.wikipedia.org/wiki/Ext4#Features</ref> | ||
* 2006 Online [[resize]] (expand) support | * 2006 Online [[resize]] (expand) support | ||
| + | * 2006 [[Extents]] replace the traditional block mapping scheme used by <code>[[ext2]]</code> and <code>[[ext3]]</code> | ||
== Activities == | == Activities == | ||
| Line 30: | Line 35: | ||
# Learn about Lazy initialization feature of ext4: https://www.thomas-krenn.com/en/wiki/Ext4_Filesystem#Lazy_Initialization | # Learn about Lazy initialization feature of ext4: https://www.thomas-krenn.com/en/wiki/Ext4_Filesystem#Lazy_Initialization | ||
# [[Review ext4 journalctl logs]] | # [[Review ext4 journalctl logs]] | ||
| + | |||
| + | == [[Mount options]] == | ||
== Related terms == | == Related terms == | ||
* <code>[[e2label]]</code> | * <code>[[e2label]]</code> | ||
* [[XFS]] | * [[XFS]] | ||
| + | * [[Reservation percentage]] | ||
== See also == | == See also == | ||
Latest revision as of 10:46, 15 February 2023
ext4 (2008) journaling file system or fourth extended filesystem is a journaling file system for Linux and it is the default file system for many Linux distributions such as Ubuntu and Debian. RHEL default fs is XFS.
Since Linux kernel 4.1 on June 2015[1], ext4 natively supports file encryption
Contents
Basic commands[edit]
mkfsandmke2fs- Creating an ext4 filesystem: (by default since 2010 will do a quick and lazy initialization [2])
- Creating an ext4 in a disk
- Creating an ext4 FS in an LV:
mkfs.ext4 /dev/vg01/lv01
- To prevent lazy initialization
mkfs.ext4 -E lazy_itable_init=0,lazy_journal_init=0 /dev/mapper/fc-root[3]
- resize2fs (See also: xfs_growfs)
resize2fs[edit]
resize2fs[4] file system resizer for ext2/ext3/ext4 (resize2fs /dev/mapper/VolGroup-lv_root). Online resize (expand) is supported in resize2fs since 2006[5].[6]. resize2fs code: https://github.com/tytso/e2fsprogs/blob/master/resize/resize2fs.c. See also: ext2online
ext4 features timeline[edit]
- 2020 ext4 fast commit support (Linux Kernel 5.10 December 2020)
- 2015 File encryption
- 2010 Lazy Initialization[7]
- 2006 Online resize (expand) support
- 2006 Extents replace the traditional block mapping scheme used by
ext2andext3
Activities[edit]
Basic
- Create an file ext4 system using:
mkfs.ext4 - Create an ext4 file system an mount it using systemd: https://codingbee.net/rhcsa/rhcsa-mount-filesystems-during-boot-time-using-systemd
Advanced
- Configure an LVM Volume with an ext4 filesystem: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/high_availability_add-on_administration/s1-lvmsetupnfs-haaa
- Learn about Lazy initialization feature of ext4: https://www.thomas-krenn.com/en/wiki/Ext4_Filesystem#Lazy_Initialization
- Review ext4 journalctl logs
Mount options[edit]
Related terms[edit]
See also[edit]
ext4e2fsck,,fsck.ext4, superblock, inode, block size, mkfs.ext4 tune2fswipefs,resize2fsstat,extents, Review ext4 journalctl logs. Read-only file system,virt-resize, ACL- File systems: clustered file system,
tune2fsmkfs.ext4,superblock, e2fsck,resize2fs,mount,df,umount, UUID,fstab - File systems:
ext4,XFS,ZFS,btrfs,wipefs,findfs,HDFS,overlay,aufs,virt-filesystems, Windows: (FAT, NTFS, ReFS), GPFS, squashfs, Ecryptfs, Encfs, FUSE, VMFS, Comparison of distributed file systems, Userspace filesystem, Resize filesystem size - File system,
du, df, find, ls, mkdir, touch, locate - ZFS, LVM, mdadm, fdisk and partitions
- XFS,
attr,xfs_growfs,xfs_info, mkfs.xfs - ext2online
- JFS2,
mkfs.jfs(Linux),jfsutilsandxfs_growfs[8] - File systems:
mount,umount,findmnt,find,swapon,swapoff,UUID, blkid, mount options:/etc/fstab,udisksctl mount,guestmount,/proc/mounts,fstrim,systemd-mount,defaults sudo,id,visudo,useradd,userdel,usermod,groups,passwd,chown,chmod,chgrp,groupadd,groupdel, Passwordless sudo, passwd (package),sudo --helpsmartctl
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