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

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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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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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largefile feature at creating file-system

Is useful to use -T largefile flag at creating a file-system for a partition with big files like video, and audio in flac format? I tested the same partition with that flag and without it, and using ...
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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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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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Ext4 support in Grub 0.9X (legacy) and Grub 1.9X (Grub2)

I'm about to setup my new USB key with Grub or Grub2. In the old days I used ext2 for the boot partition. I'm wondering if I could use ext4 for Grub2? And if use Grub 0.9X, what about support 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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How can I shrink a LUKS partition, what does `cryptsetup resize` do?

I am in progress of resizing a LUKS encrypted partition that contains a single ext4 filesystem (no LVM or something). The cryptsetup FAQ recommends to remove the old partition and recreate it, but ...
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How do I determine the new size for resize2fs?

I want to shrink an ext4 filesystem to make room for a new partition and came across the resize2fs program. The command looks like this: resize2fs -p /dev/mapper/ExistingExt4 $size How should I ...
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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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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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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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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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is it safe to backup ext4 partition with partimage , which is detected as a ext3 partition

I use partimage to backup my ext4 partition, but during backup, the partition was detected as an ext3 partition. So I'm wondering if this can cause something bad.
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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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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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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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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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ext4 used space (not -m option, not deleted files)

I'm a bit puzzled about the way ext4 reports used space. On a new Debian wheezy (testing) installation, I consistently got about 1GB extra space used with a 60GB SSD, when compared to du. I then ...
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Tell fs to free space from deleted files NOW

Is there a way to tell the kernel to give back the free disk space now? Like a write to something in /proc/ ? Using Ubuntu 11.10 with ext4. This is probably an old and very repeated theme. After ...
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Recovering ext4 superblocks

Recently, my external hard drive enclosure failed (the hard drive itself powers up in another enclosure). However, as a result, it appears its EXT4 file system is corrupt. The drive has a single ...
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Will formatting my drive TRIM my SSD?

Will a standard fresh linux (Ubuntu 11.10 to be exact) install and drive re-format (full) successfully TRIM my SSD, or do I need to do something extra? I know that ext4 will TRIM blocks on erase ...
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What's the meaning of output of lsattr

I'm wondering what the output of lsattr means.It prints so oddly as follows,when I have tried: lsattr /usr. $ lsattr /usr -----------------e- /usr/local -----------------e- /usr/src ...
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Which file system to choose for small sized files?

I have a partition and it has ~100 GB of audio files. Most of them are mp3 or ogg, each has size of ~15 MB. I update it on a weekly basis. Right now, the partition is formatted as ext4. I have read ...
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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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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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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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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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Backup or snaphot tool for ext4

I'm looking for a backup tool for ext4, which can take a copy from a running FS like /var with no collisions in system after recover such FS. I know BSD dump has an '-L' option, which tells him to ...
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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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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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How can I fsck a partition when the device reads as busy (but has been confirmed otherwise)?

I'm attempting to run fsck -p /dev/sda5 to repair errors on an ext4 partition, however the command outputs fsck from util-linux-ng 2.17.2 fsck.ext4: Device or resource busy while trying to open ...
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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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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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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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Sync writes very slow. Ubuntu 10.10, 32 bits, ext4

I am running ActiveMQ on my Macbook Pro that runs Ubuntu 10.10, 32 bits with an ext4 partition. Linux iker-laptop 2.6.35-23-generic-pae #40-Ubuntu SMP Wed Nov 17 22:32:51 UTC 2010 i686 GNU/Linux If ...
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Arch Linux fails to boot from a USB key (cannot mount selected partition)

I tried to install Arch Linux to an USB key. Things are kind of wobbly (it assumes the system has exactly one drive inside, for example) but everything installed just fine. Until I rebooted. ...
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Finding the offset for ext4 partition

I've created an image of my hd with dd, but grub was installed on it, and I'm trying to figure out how to mount the image file, but mount doesn't recognise it as an ext4 partition because of the grub ...