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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ext4: Can a clean filesystem need journal recovery?

I always thought "clean" is a synonym of does not need journal recovery. However that does not seem to be the case $ sudo file -s /dev/sdc4 /dev/sdc4: Linux rev 1.0 ext4 filesystem data, UUID=...
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203 views

do I need fsck.ext4 before mounting a filesystem?

I have a script that mounts /dev/sdc1 to /home. I do not know the state of /dev/sdc1 in advance, it could possibly be "dirty". Do I need to run fsck.ext4 before mounting the filesystem, or has mount ...
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95 views

Help about CentOS 7 apps & Driver [closed]

I'm using pc for several years but never tried Linux so I'm quite noob in this field. I'm using Autodesk maya, Nuke & will learn houdini very soon. I found that linux works faster for this apps so ...
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2answers
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Why are these files in an ext4 volume fragmented?

I have a 900GB ext4 partition on a (magnetic) hard drive that has no defects and no bad sectors. The partition is completely empty except for an empty lost+found directory. The partition was formatted ...
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2answers
384 views

ext4 file system tuning for storage partition

I searched the Internet, but I was not able to find a satisfying answer to my problem. The Problem I'm encountering currently is, that I'm transitioning my data from a NTFS Partition to a ext4 ...
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34 views

Mapping a physical sector to a filename

I just finished using ddrescue to recover the contents of a failing hard drive. It was able to recover everything but two sectors. How do I figure out which files (if any) occupied those sectors? ...
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2answers
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Precaching the list of files of the filesystem

I was wondering where and in what form a list of files and directories is stored on the ext4 filesystem. The problem is that whenever I try to access a certain directory for the first time since boot ...
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1answer
883 views

Lvreduce online on RHEL 6 or centos 6 with ext4 file systems

Is it possible to reduce a mounting lv safely at RHEL6/CentOS6 with ext4 file system? If it is, how can I do that?
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53 views

testdisk partition recovery

Looking to recover data/partition index from this disk.. ⚡ root@jg  ~  ls /dev/disk/by-label lrwxrwxrwx. 1 root root 10 May 4 21:06 4tb1 -> ../../sde1 drwxr-xr-x. 7 root root 140 May 4 21:06 .. ...
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249 views

ext4 - An entire directory disappeared?

Okay, this has me totally stumped. Background: I'm working on a cryptanalysis homework, trying to break a vigenere cipher with a 26 character key (a shuffled alphabet). Even though there are some 403 ...
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113 views

can I boot ext4 usb stick with xubuntu on from a Mac laptop?

is there a way to boot my ext4 formatted "xubuntu" USB memory stick from a Mac laptop? The laptop can identify FAT32 usb memory sticks with ubuntu at boot time, but it cannot identify mine, which is ...
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1answer
604 views

Backup Files on ext4 to external NTFS drive

Would there be any problems in copying files on my Linux system with ext4 filesystem to an external drive that is formatted in NTFS? I'm reinstalling my OS and intend to copy these files back to my ...
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4answers
448 views

Prevent file corruption

I have an application that write files into a specific directory at the FS. This system, under no circumstances, can lose a single written file. When I have some problem at the HD, like badblocks or ...
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85 views

Difference between fsarchiver and dump

What is the difference between dump and fsarchiver? Are there features in dump which are not covered by fsarchiver? Can both backup to tape storage for example?
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80 views

ETX4-fs error on startup

Hi everybody, today I run dmesg and at the bottom I found some error lines about the device mmcblk0p2. Everything works fine even with those errors but I'd like to understand the problem. I've ...
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1answer
2k views

ext4 disk space not reclaimed after deleting files

I recently got a "device full" warning for a 2 Tb external ext4 drive. I deleted a bunch of files, about 90-100 Gb of old system backups, and since I did not want to empty all trash, I deleted the ...
2
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1answer
436 views

How to use the new Ext4 Inline Data feature ? (storing data directly in the inode)

If I read the Ext4 documentation correctly, starting from Linux 3.8 it should be possible to store data directly in the inode in the vase of a very small file. I was expecting such a file to have a ...
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1answer
127 views

Is it possible to store data directly inside an inode on a Unix / Linux filesystem?

According to this Red Hat bug report (which I am trying to reproduce) it looks like the Netapp filer is able to store data directly in the inode, in case of very small files. Considering I had a FS ...
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1answer
441 views

Can't write on recently created EXT4 partition

On a new external hard drive (Intenso 05-1204-18A), I made (with GParted) two partitions : Disk /dev/sdc: 931.5 GiB, 1000204883968 bytes, 1953525164 sectors Units: sectors of 1 * 512 = 512 bytes ...
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1answer
51 views

writing to ext4, 8GB partition vs 512MB partition

I have a question which is slightly programming related, but it mostly relates to how ext4 works. I have a program which writes 128MB to a file with changing random aligned offsets. I write 256KB ...
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3answers
148 views

Deleting an Impossible File

A picture is worth a thousand words, so I want to start with that: From the image you can see that I have a ~500GB hard drive. The filesystem is ext4. On this 500GB hard drive, I have a file that ...
3
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0answers
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Problems with file system

I created a partition with EXT4 file system and when I'm writing in this partition frequently the Kernel return the following error: Jan 01 01:17:54 infobuffer360 kernel: r7:c0561280 Jan 01 01:17:54 ...
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1answer
135 views

Accidentally ran mkfs.vfat on my backup drive [duplicate]

I ran mkfs.vfat /dev/sdb (whole device, not just one partition) on my backup drive, ironic, right. Is there any way to recover my files.
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3answers
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Can I mount half an ext4 partition

I had a hardware raid array, a disk failed during migration and the controller flipped out and is unable to recover. I've written a small python script which has correctly mapped out the state of the ...
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1answer
348 views

find the cause of file corruption when copying files to a network share on an Ubuntu machine

I am copying files from my SD card to my Ubuntu server via Windows 7 using a network drive. The problem is that sometimes, 2 files out of 150, are corrupted during transfer. See here 2 example files ...
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300 views

Debian..Can't format and mount external HDD

I have been trying to format my 640GB external Hard Drive in command-line and can't seem to get it working. I have done the following in order: sudo fdisk /dev/sda (Deleted any partitions, created ...
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1answer
748 views

du and ls commands reporting wrong directory size

I'm used to the du command. I often use it with -h option. I report the result in a text file which I use to track space consumers. But I was wondered today to see a directory being reported as using ...
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405 views

Understanding ext4/jbd2 transactions

I'm trying to debug a bit of trouble I'm having with I/O latency on a system using ext4, but I'm a bit stumped in that I don't understand its journalling as well as I'd like to. What I'm wondering in ...
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1answer
212 views

Smallest file block size (ext 3, 4)

I'm curious, what is the smallest size a file can really be on Linux? (Assuming Ext3 fs, so why not ext4 fs as well). Sure you can write a file that only contains one byte, or maybe even less; but ...
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0answers
190 views

Red Hat Enterprise Linux 6.5 remounts root filesystem read-only after hibernating

I have a Lenovo ThinkPad T430 running Red Hat Enterprise Linux 6.5, kernel 2.6.32-431.30.1.el6.x86_64, and my filesystem structure consists of a master LUKS partition holding two logical volumes, one ...
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2answers
779 views

Which file system is better for Ceph?

I've read the Ceph OS recommendations document, but still I have a question. Which file system is better for Ceph? XFS, ext4, or something else?
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Have I destroyed data on drive?

I stupidly ran the following command on an external ext4 USB disk, typing /dev/sdb instead of /dev/sda which was the new disk I was setting up: dd if=/dev/zero of=/dev/sda bs=512 count=100 These ...
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Restoring data from NTFS formatted pre-ext4 partition

MS recovery just formatted my 1TB Backup disk to NTFS which was ext4 before. It was an MBR disk before but now it's a GPT one. Now I'm on SystemResqueCD and can check with the testdisk. What is the ...
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3answers
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Why doesn't my exactly 100 MiB partition at 1 KiB block size have the corresponding available blocks/space?

I have a very high density virtualized environment with containers, so I'm trying to make each container really small. "Really small" means 87 MB on base Ubuntu 14.04 (Trusty Tahr) without ...
2
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3answers
385 views

Why creating partitions in linux is a good solution for easy recovery?

I have heard if you don't make partitions in linux, it is so hard to recover the data. And if you make few partitions it would be easy to recover the data. for example if you make /par1 /part2 /part3 ...
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2answers
174 views

15 GB of unaccounted-for space in filesystem

[nathanb /mnt/work] sudo du -hs . 23G . [nathanb /mnt/work] df -h . Filesystem Size Used Avail Use% Mounted on /dev/sdb1 40G 38G 6.4M 100% /mnt/work Where is the other 15 GB? /dev/...
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5answers
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Why can't I delete my files?

I copied some files from a data DVD to /home/emma (ext4), and all of the files are read only. This is what all of the files are like: emma@emma-W54-55SU1-SUW:~$ stat cd/Drivers/Drivers_List.rtf ...
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2answers
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ext4 corruption found in superblock, but filesystem can be mounted

After a crash, I've got an Ext4 filesystem (on an LVM LV) that gives the following error when running fsck.ext4 -nf: e2fsck 1.42.12 (29-Aug-2014) Corruption found in superblock. (blocks_count = 0). ...
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1answer
73 views

What is this data that keeps reappearing after partition delete + new partition creation?

I deleted a big extended partition containing an ntfs logical partition with high percentage of occupied space and from that extended partition I made a new, smaller extended part. In it I ...
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1answer
528 views

Recovering from bad superblock on external drive

read a few similar questions/posts and tried the solutions, still stuck. My scenario is simple, external ext4 drive was powered off (via cat) while operating, and failed to mount on boot. As I dug ...
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1answer
297 views

Write to ext4 filesystem hang while lazyinit in background

I am running SUSE 12 on a node that has 6TB disks attached with EXT4 filesystem initialized. Lazyinit in the background takes atleast 24 hrs to complete. Write performance to the disk is significantly ...
2
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1answer
552 views

“First orphan inode” in tune2fs output

I ran tune2fs -l /dev/sda on my production server today and got the following output: tune2fs 1.42.9 (4-Feb-2014) Filesystem volume name: <none> Last mounted on: / Filesystem UUID: ...
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1answer
83 views

Tiny directory on ext4 file system taking up 2024 blocks? [closed]

I have an ext4 file system on my work computer and I came across a directory that is taking up >1 mb of space. There are 7 entries in the directory. The directory hasn't ever contained more than 20 ...
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1answer
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Can I find out if a given ext4 block is in the inode table, and if so, can I pick it out of a journal with no header by hand?

So en route from my old laptop to a new one my old laptop's hard drive got some physical damage. badblocks reports 64 bad sectors. I had a two-month-old Ubuntu GNOME setup with a split / and /home ...
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Why doesn't the owning group get the executable bit? [duplicate]

Playing with ACL's: [root@rex web]# pwd /media/web [root@rex web]# ll -d drwxr-xr-x. 2 root root 4096 Jan 1 14:31 . [root@rex web]# setfacl -m d:g::rwx . [root@rex web]# setfacl -m g::rwx . [root@...
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1answer
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What are the implications of using an inode_ratio of 16384 in terms of storage use on ext4?

I'm assuming that this means that if the average file stored (including directories etc) is less than 16384 bytes, it may be possible to run out of inodes before using the full storage capacity of the ...
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369 views

Size Range of ext4 Filesystem Journal

The minimum and maximum sizes respectively for the ext3 filesystem journal are 1,024 blocks and 102,400 blocks. Similarly — what are the minimum and maximum sizes for the journal on an ext4 filesystem?...
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2answers
543 views

rsync hangs unless I defrag ext4 filesystem

I have a XBian server (Raspberry Pi version of Debian) running rsync via inetd (not the native dæmon). I am serving a couple of directories on an ext4 filesystem (on a USB disk) as individual modules (...
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1answer
67 views

Delay before new/modified file appears

I'm seeing two separate cases where there's a (random?) delay before a new or modified file appears. The first case is my Rails development environment: I modify a code file (in vim) and save it, ...
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1answer
350 views

automount ext4 external hdd partition for owned by specific user

I'm trying to figure how to mount an ext4 formatted external HD with permissions for a specific user using autofs, but I'm only able to mount it as owned by root. I have read that ext4 mount points ...