ext4 (fourth extended filesystem) is a journalling file system for Linux, developed as the successor to ext3. Use this tag for question that are ext4 specific, generic file system related questions should use tag [filesystem]

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If I grow an ext4 partition, will it increase the number of inodes available?

If I create a small filesystem, and grow it when I need to, will the number of inodes increase proportionally? I want to use Docker with the overlay storage driver. This can be very inode hungry ...
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103 views

tune2fs - how much space to reserve on large ext4 filesystem

I am aware that there are several questions concerning how much space to reserve on a filesystem using tune2fs -m, but some of the advice is contradictory, some seems to be relevant only to the ...
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Files Just Go Missing On ext4 Partition (within TrueCrypt Volume)

There are spooky things happening on one of my external hard drives. It's a 3 TB hard drive with: one big partition taking up basically all the storage space there is, and a pretty small partition ...
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43 views

Can I create a file on ext4 with a depth > 1 for testing purposes?

In order to test an analysis tool, I need a file where the depth (eh.eh_depth) is greater than 1. I've tried a couple of things: A large file (1GiB) Creating hundreds of smaller files (1MiB), ...
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1answer
57 views

Decrypt a portion of a corrupted drive

I have a hard drive that got corrupted after a doing an MTP mounting of a cell phone. It was created under Fedora Core 20 using defaults. Originally, I thought I did it as an ext4 partition. I ...
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354 views

ext4 & jbd2 dirty metadata

I have an embedded system based on the RiotBoard, I have the main file system on the MMC set as read-only, and an 8gb usb flash drive for writeable storage. rootfs is debian, linux kernel version 4.3....
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1answer
38 views

Any way to help “visualize” the superblock, filesystem, group descriptors, etc

I've been reading a lot about filesystems, trying to learn all I can in depth, but I'm having trouble really visualizing some of it, especially when it comes to things like the superblock, group ...
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28 views

Are the links between the inode and data blocks of a file removed when deleting the file?

Suppose there is only one hard link to a file. When rm the hard link, the inode and data blocks of the file will be marked as unused. But are the links from the inode to the data blocks of the file ...
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1answer
252 views

Why is OS constantly writing to disk (ext4) on a Ubuntu 14.04 machine? Is it normal?

I'm quite sure it didn't happen before I started using LUKS and LVM on my disk (2 or 3 weeks ago), but now root user is constantly (every 2-3 seconds) writing (not reading, just writing) on disk and I ...
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82 views

Untar a filesystem to device as normal user but maintaining the correct UID and GID

I'm doing quite a bit of development using Yocto to target an embedded system. As its final output, Yocto generates a tarball of the filesystem, which I then untar onto an ext4 partition of an SD ...
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3answers
364 views

How can I identify the filesystem/partition type

My hard drive got corrupted at some point after mounting an mtpfs system. I would ask how to fix that, but I'm not confident about the partition and file system types. My OS is new Fedora Core 23, ...
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229 views

GlusterFS on EXT4 is stable enough?

I saw an Article on Rackspace about setting up GlusterFS without using XFS but instead, it uses EXT4. I've been wondering about setup like that since before, to know whether it is production ready (...
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1answer
87 views

Disappearance of files in all ext4 filesystems of a Debian server

Apparently the disappearance of files and directories occurred in all ext4 filesystems, including files and directories usually "read-only" in /var and /usr, like binaries installed for gcc, and ...
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1answer
234 views

Choosing File Format of /home between NTFS and Ext4, Understanding Trade Offs in Performance vs Data sharing with WinXP in Dual boot [closed]

I have Win Xp on first Primary Partition. I am leaving another 2 primaries for a future possible Win install. I am planning my Logical partitions to install a Linux Mint. I read that a separate /home ...
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1answer
579 views

File type inode/x-corrupted

My system had an unexpected shutdown. Now when I open the file from pcmanfm or nautilus I get file corrupted error. Strangely the files are accessible just fine if I launch pcmanfmas root user. The ...
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1answer
100 views

how to get crtime of a file in an ext4 partition as a single number or string

I am seeking a method of getting the crtime of a file in hexadecimal or decimal in unix epoch seconds instead of in a date and clock format and with no additional output. This command adds additional ...
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1answer
63 views

Ext4: I/O errors on a clean external drive

So I've an external Seagate hard disk that I used to mount on my Mac through Paragon ExtFS. For some unknown reason it stopped to mount on my Mac due to I/O errors - I may have removed the drive ...
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21 views

fat32 partition overwritten by Mint image

Was Running Mint 17.1 Two Kingston USB devices attached accidentally written a Mint image the the archive Kingston by the image writer, and lost my fat32 partition with important data collection. ...
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Flash drive fat32 partition overwritten by Linux Mint 17.1 image writer - need to recover [closed]

Ah Yeah...Mint 17.2 image is written onto a Kingston flash drive (8GB) and overwritten a fat32 partition. I can take You to the moon if You tell Me that, those files aren't lost ones. ///the image ...
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1answer
65 views

Comparing 2 partitions on identical disks

I have 2 physically identical disks. Each with 1 partition: | Disk | FS | Size | Comment | |----------+------+----------+----------------------------------| | /dev/...
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1answer
135 views

How can I zero the unused blocks on my filesystem in order to minimize the compressed disk image size? [duplicate]

If I dd my disk and compress the image with lzma or lzo the image is still big. The partition is 10GB used, 90GB available. But the image still around 20GB. I believe that is because I have copied ...
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47 views

How do distribution installers avoid ext2/3/4 initialization?

When I format a volume with ext4, I have two options regarding initialization. I can either use lazy_itable_init=1 (the default setting) to delay initialization until after the volume is first mounted,...
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209 views

ext4 reported as clean by fsck after hard reset: Is that normal?

My root-partition is formatted as ext4-filesystem. I notice that, whenever my machine crashes and I have to hard-reset it, when booting up again and the root filesystem is checked this step takes a ...
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1answer
268 views

How can I convert a disk from ext4 to ext2?

I have Ubuntu with a root volume using ext4. I need to downgrade it so that it is using ext2. Is there a way to do that?
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132 views

ext4 inodes in use for files that are missing

Executive summary: Every tool I've tried confirms lots of inodes in use on this ext4 partition Every tool I've tried shows me that there are no files on the partition It's not files held open and ...
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37 views

What happens to directory entry when a file is renamed

What exactly happens to the directory entry when a file is renamed? Is it that the entry of the oldfile is flushed and the newfile is replaced at it's place or a completely new entry is made at the ...
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1answer
302 views

Trying to mount ext4 partition from eMMC gives “Invalid Argument” error

I'm trying to set up a custom Linux installation on an Intel Atom (Baytrail) based Android tablet, using Qt 5.5 for device creation. The build system is based on the Yocto project and builds an ...
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1answer
4k views

How to take snapshot of an ext4 filesystem

Is there any way we can take a snapshot of an ext4 filesystem so that we can revert back to it later?
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257 views

How to use tune2fs?

I want to adjust the time interval between ext2, ext3 and ext4 filesystem checks to 180 days? I know that I have to use tune2fs -i 180 but I am not sure about the arguments
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2answers
138 views

Why debugfs doesn't show crtime in nanoseconds?

I am using: debugfs -R 'stat <7473635>' /dev/sda7 to get the file creation time (crtime). Inode: 7473635 Type: regular Mode: 0664 Flags: 0x80000 Generation: 1874934325 Version: ...
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1answer
116 views

Content Explanation Of: /proc/fs/ext4/device_name/mb_groups

I've been wondering, what are the explanation of the columns in the /proc/fs/ext4/device_name/mb_groups file. The columns are: #group: free frags first [ 2^0 2^1 2^2 2^3 2^4 2^5 2^6 2^7 2^8 2^9 2^10 ...
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Recovering ext4 superblock

I had an ext4 filesystem in an LV which got destroyed because I accidentally shrunk the partition it was in way too small. After expanding the partition back to the original size I put a new ext4 FS ...
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303 views

What do “extents” feature do in ext4 filesystem in linux?

I was reading about the ext4 filesystem that it supports compression, encryption and a feature called extents which is used to save disk space. What are extents and how are they are effective for ...
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2answers
486 views

LVM Filesystem recovery

I was trying to resize my LUKS crypt following this https://wiki.archlinux.org/index.php/Resizing_LVM-on-LUKS and I got to the partition resize with parted and seriously screwed things up. I typed 870 ...
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1answer
100 views

EXT filesystem family: Why does the first superblock start at offset 1024?

I was brushing up and diving deeper into filesystem anatomy and in numerous resources it is said to be a requirement that the very first superblock start at an offset of 1024 bytes. I started looking ...
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My ext4 partition is corruption-prone possibly because of suspend

I'm using an encrypted ext4 main partition on a Lenovo i7 laptop running Ubuntu 14.04 LTS, currently using the 3.13.0-53-generic x86_64 kernel. After running for multiple weeks without shutting down ...
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2answers
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How to fix intermittant “No space left on device” errors during mv when device has plenty of space?

Ubuntu 14.04 on a desktop Source Drive: /dev/sda1: 5TB ext4 single drive volume Target Volume: /dev/mapper/archive-lvarchive: raid6 (mdadm) 18TB volume with lvm partition and ext4 There are ...
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1answer
98 views

EXT4 requiring twice as much storage space - Ubuntu / Beets

I have a question I'm struggling to research an answer for. I have am building a Ubuntu media server at home and decided to carve up my 2TB bulk storage disk into various partitions. I created a ...
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1answer
117 views

SSD failiure. grub rescue sees files, but I can't mount drives

I have a 2 year old SSD that apparently has died. 2 out of the 3 partitions are completely unmountable (only EFI boot partition mountable). When i turn on my computer I am greeted with grub rescue ...
3
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1answer
66 views

Cache atime writes

Is there a way to set atime writes to be cached for a very long time? I need atime (that is to say, relatime won't cut it), but I don't want it to effect performance so much. Data loss in of atimes (...
3
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1answer
377 views

ext3 vs ext4 - same disk size, less usable disk space under ext4 comparing to ext3. why?

Files copied from ext3 filesystem do not fit on same size ext4 filesystem. How to reproduce: create two 1GB files, setup loop device for each, create filesystem one ext3, one ext4, mount, rsync ...
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250 views

EXT4 Journaling - Problem

Basically my root (/) ext4 partition keeps being mounted as read-only when I apply internal journaling feature. I understand that this should be default, but today I had been trying to apply external ...
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4answers
558 views

How do I create small disk image with large partitions

I am building a disk image for an embedded system (to be placed on an 4GB SD card). I want the system to have two partitions. A 'Root'(200Mb), and a 'Data' partition(800Mb). I create an empty 1GB ...
5
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1answer
163 views

How to change the extent size in the ext4 file system?

As you can read here , ext4 file system has an extent feature that groups blocks into extents. Each of them can have up to 128MiB contiguous space. In e4defrag , there are lines similar to the ...
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171 views

Why can't I write to my ext4 partition even with 777 permessions?

When I touch a new file for example I get: touch: cannot touch 'file': permission denied It is a partition that is mounted in the /media directory on demand. I am the owner and I've had it's ...
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How to obtain the whole disk activities triggered by file systems under linux?

I want to record the disk access activities called by OS. Such data I want to record are received by disk from OS, including disk sector number, request length, arrival time, read or write. To be ...
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Reinstalling Debian: ext4 partition is not primary

I previously had a grub bootloader with crunchbang and win7. Since then I reinstalled win7 which now boots it automatically. I stuck in a Debian install CD that brings me to the stage in the above ...
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217 views

7-Zip slows down over time on Ubuntu but not Windows

I have a directory called Pages of 2.2 million HTML files (about 80 GB) on an Ubuntu server. I compressed it with 7-Zip using this command: 7z a -mx=9 Pages.7z Pages It took around 5-6 hours to ...
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1answer
320 views

Mark an ext4 filesystem as read-only

I want to create an ext4 filesystem, and add some files to it, then "freeze" it so it is henceforth read-only. I know it's possible to use the ro mount option. But is there some way to indicate in ...
2
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1answer
268 views

What should I consider when choosing a filesystem for a personal disk archive / cold storage?

I have a few TB of media files that never changes and that I need to store safely. Since it's a personal business it's overkill to set up a disk server et cetera, so I use the simple solution of ...