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

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What are EXT4 Security Labels?

During Gentoo installation of Gnome keyring, I am told to switch on EXT4 Security Labels, which is described in the kernel documentation by: Security labels support alternative access control ...
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What is a generic way of finding out whether the kernel has ext4 (or other) bugs?

From /. found this worrisome post by Theodore Ts'o. Turns out ext4 has some journalling problems. How can I quickly find out version numbers of susceptible kernels for this and other bugs?
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how to restore a logical partition to it's original ext4 format

This question is following Unable to mount /home/ partition after reinstalling grub after reinstalling windows 7 where the diagnostic was that installing windows 7 deleted my /home partion, lovingly ...
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Fastest way to get list of all file sizes

I'm trying to create a graph of the distribution of file sizes on my ext4 system. I'm trying to write a script to scrape this information from my computer somehow. I don't care where the files are ...
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Unable to mount /home/ partition after reinstalling grub after reinstalling windows 7

I've reinstall windows 7 on it's asignated partition and, as usually, it override the MBR with it's own stuff and, thus, it was not possible to boot to my ubuntu 12.04 partition. I followed the step ...
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A lot of errors on ext4, however smart doesn't show any errors

I have a Debian box with additional ( it is not a system disk ) 1.5Tb sata hdd (wd caviar green). There is only one partition on the whole disk. Disk is used for backups from remote system (with ...
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Is there any difference between e2fsck and e4fsck on CentOS / RHEL systems?

ext4.wiki.kernel.org makes it sound like e2fsck was simply renamed to e4fsck so that e4fsprogs and e2fsprogs could coexist without overlapping. However, there is no mention of any difference in the ...
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recovering ext4 partition after dd'ing over start of HD

I accidentally used dd and wrote over the first 208MB of my external disk. What I wrote over is a partition on its own (Debian nestinstaller) so what I see now is not my old (now damaged) ext4 ...
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How to fix a fragmented ext disk - myth or truth?

I just read this article about the virtually non-existent disk fragmentation on *nix filesystems. It was mentioned that due to the way ext handles writing data to the disks, fragmentation may only ...
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To use -c0 -io in file-systems with journal

I've several partitions with EXT4. Now, I would want if it makes sense to use tune2fs with flags -c0 (max-mount-counts) and -i0 (interval-between-checks) in the partitions with a journal file-system ...
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Can't mount EXT4 hard drive after mounting it in windows

I have a 2TB Western external HDD. Its original filesystem was NTFS but I formatted it to EXT4. I had no problem in Linux; But today after I mounted it using ext2fsd in a windows box, I cant mount it ...
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Superblock corruption on every boot

I have a Linux Mint 12 install on my laptop. Yesterday I powered it off like I always do and this morning when I started it I was greeted by an error screen. (Translated from Swedish) Fatal ...
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corrupted library after hard shutdown

yesterday night my laptop executes a hard shutdown because my battery was out of charge. After the reboot Xorg hangs and the troubleshooting was pretty hard. A first file system check of my ext4 ...
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Howto configure autofs to work with usbsticks formatted with differend filesystems

I have some USB-sticks using fat32 as filesystem and others using ext4. Now I want to configure autofs to mount the sticks automatically. To make sure that the user can write to fat32 sticks I use ...
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Recreating EXT4 partition without losing data [duplicate]

Possible Duplicate: Can't mount EXT4 hard drive after mounting it in windows I have a 2TB Western External USB harddisk. I formatted it to EXT4. one time I plugged it to a windows ...
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No access to symlink folder on NTFS partition

I am using an NTFS parition for storing data I like to access both from Ubuntu and Windows 7. On my Ubuntu HOME partition, I like to link the folder Assets in order to access it from an application ...
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Is it possible to change Inode count on an ext4 filesystem? [duplicate]

Possible Duplicate: How can I increase the number of inodes in an ext4 filesystem? I have a homemade NAS with Debian Wheezy 64bit. It has three disks - 2x2TB and 1.5TB, pooled together ...
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Why my partitions don't show the right capacity on a 4096 byte physical block hard drive?

After reading a lot about why newer 4096 byte physical block hard drives should be partitioned taking care of alignment (Linux on 4KB-sector disks: Practical advice, What is partition alignment and ...
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File system jfs/btrfs/xfs/ext4 [closed]

I was looking into some of the requirement, where huge amount of recursive files are written and deleted and looking forward if any FS (file system) as such gives advantage on others. I am trying to ...
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ext4 directory lists as a file

I'm working with a large (8TB) EXT4 filesystem in linux. After a power outage, the filesystem wouldn't mount. fsck is taking weeks to complete, but i ran testdisk and i'm able to see my partition ...
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How to limit ext4 filenames to only those filenames legal in FAT?

The ext4 filesystem allows some characters that FAT does not allow, such as :. This has caused me much grief in the past when trying to move files, especially as KDE will delete such files instead of ...
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ext2/3/4 reserved blocks percentage purpose

I know that this feature dates back 20 years but I still would like to find out What is the purpose of the reserved blocks in ext2/3/4 filesystems?
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Keep ext4 journal on another system, how much space would be necessary?

I'm going to move journal to another partition, but I don't know how to correctly caculate the size needed for journal? I'm running ext4 file system with 15GB capacity.
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disabling journal vs data=writeback in ext4 file system

What is the difference between disabling journal on ext4 file system using: tune2fs -O ^has_journal /dev/sda1 and using data=writeback when mounting? I thought ext4 - journal = ext2. means when we ...
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Recover a reiserfs hard disk

I'm unable to mount my 300GB external (in external enclosure) HDD's single partition. None of the fsck tools add anything, they cannot even recognize the partition. I had forgotten whether I had used ...
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Different UID/GID when using an ext4 formatted USB drive with another computer

The problem of using a filesystem like ext4 on a USB stick or memory card is that when it's mounted into another system the disk's UID/GID might not be present. Can this be fixed with a mount option? ...
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Creating an ext4 partition fails with “invalid blocks count”

Environment: - Virtual machine on VMWare ESX 4.0 - OS: fully up to date RHEL 5.8 After adding a new (virtual) disk I want to create an ext4 partition on LVM on this disk. Steps taken so far: $ sudo ...
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e4rat in Fedora 15

Has anyone tried installing e4rat and optimizing boot-time in Fedora 15? This ext4 defragmenting and optimizing utility works wonderfully in Debian. I am wondering if someone has replaced Fedora's ...
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How to configure a filesystem+LVM for effective usage of SSD?

ext4 is one of the filesystems recommended for using on SSDs (with a number of built-in techniques and advices how to tune it for better performance and wear-levelling of SSDs). I want to install a ...
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Is disabling barriers for ext4 safe on a laptop with battery?

The manual page says about the barrier option for ext4: Write barriers enforce proper on-disk ordering of journal commits, making volatile disk write caches safe to use, at some performance ...
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Find which files are affected by bad blocks on ext4 filesystem

I have an ext4 filesystem that recently developed some bad sectors. Running fsck.ext4 -c finds and remembers the bad blocks. How can I find which files (if any) included these bad blocks so I can ...
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How are files laid out in ext2/ext3/ext4?

A few days ago all my metadata on a ext4 format flash card was overwritten. I am now going to speculate on how this happened. This is pure speculation. It happened just after I used a different ...
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Allocate file at a specific offset in ext3/4

For benchmark and testing purposes I need to be able to allocate a file at a specific offset from the start of the partition. When I create a new file normally, its blocks are placed wherever the file ...
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Grub 2 installed on-partition - how to not embed it

My friend installed ArchLinux on a MacBook Pro alongside Mac OSX and Windows to try it. He's power user, so I only needed to help with the bootloader. Arch Linux's described installation of GRUB did ...
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Significant difference in speed between fsck using ext3 and ext4 on Debian Squeeze

Recently I installed Debian Squeeze, first using ext3 and then again using ext4 on the same machine. The automatic fsck done after a certain number of mounts is much faster using ext4 (about 1 min) ...
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Why is (free_space + used_space) != total_size in df? [duplicate]

Possible Duplicate: ext4: How to account for the filesystem space? I have a ~2TB ext4 USB external disk which is about half full: $ df Filesystem 1K-blocks Used Available ...
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Fragmentation and ext4

Suppose I have a sparse file F on a Linux ext4 filesystem, and process P1 is writing to a disjoint 50% subset of F while P2 writes to the other 50% of F. I would like to minimize fragmentation while ...
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What does this Linux kernel trace mean?

I’m running a linux server at home which is mostly a file and e-mail server and a digital video recorder. All the data goes on an ext4 partition on a software raid-6. Every now and then (sometimes ...
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What does fsck -p (preen) do on ext4?

I was reading a blog post about filesystem repair and the author posted a good question… fsck -p is supposed to fix minor errors automatically without human intervention. But what exactly will it fix ...
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what is commit=0 for ext4? does mdadm not support it?

I see this in my dmesg log EXT4-fs (md1): re-mounted. Opts: commit=0 EXT4-fs (md2): re-mounted. Opts: commit=0 EXT4-fs (md3): re-mounted. Opts: commit=0 I think that means that dealloc is disabled? ...
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Unable to mount a second hard drive in Ubuntu Server

I am adding a second drive to my Ubuntu Server. It was previously in a FreeNas system, but I got rid of the XFS partition and created an ext4 partition (in an older Ubuntu system). I then backed up ...
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Recover formatted ext3 partition

Suppose you have an ext3 partition which was unfortunately formated as ext4 partition (and where now are some but not a lot new files on it). Is there any way to recover (some) files from the old ext3 ...
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ext4 overrides my commit=100 mount option with commit=0

Here is the relevant line from my /etc/fstab file: UUID=f51aa298-9ce4-4a19-a323-10df333f34f5 / ext4 data=writeback,noatime,barrier=0,errors=remount-ro,commit=100,nobh,nouser_xattr ...
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Use testdisk and gpart information to mount ext4 partition

I am trying to recover the ext4 partition table of a 2TB disk, where I have 900.000 files. I have cloned the original HD and now I am working on the cloned HD. And I am running Parted Magic Live CD. ...
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ext4: How to account for the filesystem space?

I've recently formated a 1.5 TB drive with the intention of replacing ntfs with ext4. Then I noticed that the files I saved don't fit on the new partition. df: ext4 (ext3 & ext2 show the same ...
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ext4 formatting weirdness

Just got a new 2TB hardrive for my Debian Squeeze Box. Trying to format it in ext4 after creating a Primary partition using cfdisk. I just did this exact process with a 120GB drive on the same ...
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How to make ext4 filesystem sparse?

I am using Linux as guest OS in VirtualBox. I deleted huge number of files from its filesystem. Now i want to shrink the filesystem image file (vdi). The shrinking works by compressing filesystem ...
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Why is deleting files by name painfully slow and also exceptionally fast?

Faux pas: The "fast" method I mention below, is not 60 times faster than the slow one. It is 30 times faster. I'll blame the mistake on the hour (3AM is not my best time of day for clear thinking :).. ...
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Can I convert an ext3 partition into ext4 without formatting?

my home directory is on a separate partition which still uses ext3. Is there a way to convert this partition into ext4 in a non-destructive way?
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Defragging an ext partition?

Why don't ext2/3/4 need to be defragmented? Is there no fragmentation at all?