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Questions tagged [ext4]

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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3
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1answer
66 views

How exactly is ext2 upwards-compatible?

I read somewhere that an operating system which knows nothing about ext3 and ext4 (i.e. antique Linux version) is able to read/write to ext4, and it detects any ext4 file system as ext2. I am not ...
0
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1answer
3k views

Cannot extend partition beyond 2TB on AWS Ubuntu

a@b:~$ sudo growpart -v /dev/xvda 1 update-partition set to true resizing 1 on /dev/xvda using resize_sfdisk_dos 6291456000 sectors of 512. total size=3221225472000 bytes WARN: disk is larger than 2TB....
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1answer
401 views

How is free disk space on ext4 calculated?

I know there are tools like df which show the disk space remaining on disks but I could not find any info on how this tool actually gets this info. I would imagine the filesystem keeps track of this ...
2
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1answer
3k views

how to enable xattr support in Debian 9 (Stretch)

I have added user_xattr in ext4 but when I remount it doesn't show xattr & I installed attr & attr_dev # <file system> <mount point> <type> <options> <...
0
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1answer
357 views

Manually backup superblock - how to & does it make sense?

Background The first block of an ext4 filesystem is called the superblock - it contains essential metadata. There are backup copies of the superblock scattered throughout the filesystem; they can be ...
1
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1answer
104 views

formatted drive as ext4 in another PC. can't mount in another PC

so I have a single partition ext4 drive that I formatted in my Ubuntu desktop. I connected it to another PC running debian and I cannot mount it. Any ideas on how to fix it? some info: => sudo ...
2
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2answers
1k views

How to erase gpt partition table and how to make old partition forget mount information

We have Beaglbone black based custom board with 256MB RAM and 4GB eMMC. We have script to flash software on the board. Script erases gpt partition table using following commands #Delete primary gpt (...
1
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1answer
382 views

ext4 with corrupt filesystem structure

Something has corrupted my ext4 partition on my debian server. The server had an uptime of about 1700 days, and unfortunately the UPS did not have enough battery to last a whole day power outage. I ...
8
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1answer
10k views

How to make an ext4 formatted usb drive with full RW permissions for any linux machine?

I want to format my USB stick to ext4 and just use as I would any other typical non-linux format drive (FAT32, exFAT, NTFS). That is to say, I want to be able to plug the usb stick into any of my ...
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2answers
98 views

How to identify relevant parts of an ext4 partition

Background: I need to clone ext4 partitions from an eMMC using uboot (and if neccessary custom bare metal code). I copied the whole thing using mmc read and found that most of the partition is empty, ...
3
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2answers
823 views

Why is 67108864 the maximum bytes-per-inode ratio? Why is there a max?

Formatting a disk for purely large video files, I calculated what I thought was an appropriate bytes-per-inode value, in order to maximise usable disk space. I was greeted, however, with: mkfs.ext4: ...
0
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1answer
160 views

ext4 mounted on / and tmp consuming disk space

I am using an Ubuntu 16.04 LTS. I ran into an unusual problem with my disk usage. Some of my applications were aborted with the message on the terminal stating "not enough disk space available". The ...
2
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1answer
184 views

How to defragment files in size less than 100MB only in ext4 filesystem

I have a very basic idea: I would like to defragment files in size less than 100MB only in ext4 filesystem. Since there is no option for that in the defragmentation tool (e4defrag), any ideas how I ...
0
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1answer
370 views

Can Ubuntu use an EXT4 hard drive through a USB-SATA dock?

I have a linux system with two 3T EXT4 formatted data hard drives in addition to a system SSD. They are not formally raided, I just rsync from one to the other from time to time to keep two copies of ...
0
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1answer
2k views

SSD partition aligned

I need to prepare the file system of an SSD disk in a way that a Database Administrator pointed me to, which would be a way optimized SSD to work. I have a disk: SSD: Samsung 500 GB SATA III 6Gb/s - ...
7
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2answers
1k views

rmdir failed to remove empty directory

I have a problem with removing empty dir, strace shows error: rmdir("empty_dir") = -1 ENOTEMPTY (Directory not empty) And ls -la empty_dir shows nothing. So i connected to the fs (ext4) with debugfs ...
2
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0answers
1k views

EXT4 app2sd link2sd partition repair with bad superblock . Partition cannot be mounted on Android but will mount RW w/ su on Linux Live

I have a 128gb micro sd formatted as ext4 10gb for app2sd 2nd ext4 partition ( p2 ) on my Android 6 phone . All my apps ( 80%) stay on that ext4 partition . Now app2sd cant load this partition - "...
4
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1answer
329 views

Moving millions of small files results in “out of space” error

I't trying to move around 4.5 million files (size ranges from 100 - 1000 bytes) from one partition to other. The total size of the folder is ~2.4 GB First I tried to zip it and move the zipped file ...
0
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1answer
516 views

“VFS: Can't find ext4 filesystem” on ZFS disk

I am getting many of these messages on one of my systems: [ 348.515157] EXT4-fs (vda9): VFS: Can't find ext4 filesystem [ 348.517587] EXT4-fs (vda9): VFS: Can't find ext4 filesystem [ 348.519944] ...
2
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1answer
95 views

Recover file system after overwriting first sectors

I have accidentally overwritten the first few GB of my external hard drive with dd. Previously the file system had a NTFS file system of about 3TB and at the end an 1 TB ext4 file system containing my ...
4
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0answers
449 views

Trouble mounting 5Tb external USB device

I purchased a Seagate Backup Plus 5 TB USB 3.0 Portable 2.5" drive as I've recently maxed out the 1TB drive I have connected to my RPi2 running ArchLinuxARM and serving up music around the home (...
2
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0answers
176 views

Are there any known ext4 issues that could randomly cause files to become zero-bytes in length?

My company produces Android devices running Linux 3.4 and we have seen that sometimes but rarely a file on the ext4 emmc file system will suddenly become zero-length. Normally I would suspect an ...
0
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1answer
51 views

Connecting an external HDD in Windows 8.1

I have a double boot Linux/Windows 8.1 laptop and connect an external HDD formatted in ext4 to it. It works fine with Linux and I do not intend to use it with Windows. I am wary that when I boot ...
14
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5answers
4k views

Millions of (small) text files in a folder

We would like to store millions of text files in a Linux filesystem, with the purpose of being able to zip up and serve an arbitrary collection as a service. We've tried other solutions, like a key/...
2
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0answers
146 views

Looking for 4 TB cross-platform filesystem for standalone disk

This is partially coming from https://superuser.com/questions/227664/cross-platform-file-system-open-source/1274486#1274486 I have been looking for a filesystem which is supported on both platforms. ...
0
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1answer
741 views

How do I mount an Ext4 File System with an alternate SuperBlock?

I know how to get back a working file-system(FS), the usual way, by running e2fsck -b alt_SB_no /dev/sdX which will fix my FS. I have an ext4 image-file that is corrupt - I want to patch in just ...
1
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0answers
413 views

How to recover my ext4 drive accidentally overwritten by an mkswap?

I had my USB hard drive partitioned with ext4. Then I accidentally did mkswap /dev/sda1 swapon /dev/sda1 Now I cannot mount my drive and it seems like my data is gone. Is there any way to recover? ...
1
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1answer
70 views

Virtualbox dynamically-allocated disk *.vdi keeps growing

When using Linux in Virtualbox and dynamically-allocated disk, it keeps growing even though almost half of space is free: Filesystem Size Used Avail Use% Mounted on /dev/sda2 94G 12G ...
1
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1answer
1k views

Why is mounted nas showing 0 inodes on users partition?

I am using a NetGear ReadyNAS machine as a NAS for our server. The server is a linux CentOS 6.6. The server is run using Rocks cluster, with all our users' home directories located on the NAS. My ...
0
votes
1answer
62 views

Recovering from an AMNR Hard Drive error (ext4)

I am trying to recover whatever data I can from a bad partition on a hard drive. Unfortunately fsck failed to resolve the issue. The output from mount is as follows: $ sudo mount /dev/sda3 /mnt/ ...
5
votes
1answer
4k views

Why do I have “errors=remount-ro” option in my ext4 partition in my Linux?

In mount man page errors=remount-ro is an option for mounting fat but this option doesn't appear in ext4 options catalog. I know what this option means: In case of mistake remounting the partition ...
1
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1answer
132 views

After reboot files losts and old versions restored!? Ext4

A linux 3.2.0-54-generic, Ubuntu 12.04 on Vmware was rebooted and then files disappeared and very old versions appeared on /etc. It gave problems at booting, I copy part of dmesg [ 18.824677] ...
1
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2answers
5k views

How can I create an ext4 ramdisk?

First, I have create the directory that I will want to mount to. mkdir /mnt/ramdisk Now, I could easily turn this into a ramdisk using ramfs or tmpfs via mount -t tmpfs -o size=512m tmpfs /mnt/...
8
votes
1answer
10k views

What should I do to force the root filesystem check (and optionally a fix) at boot?

Yesterday, one of our computers dropped to grub shell or honestly, I am unsure what shell it was when we turned on the machine. It showed that it can't mount the root filesystem or something in this ...
1
vote
1answer
553 views

Hard drive unreadable

The 500GB Seagate ST9500420AS (D005SDM1) hard drive in my 2011 Dell XPS 15 crashed the other day and, although I had the most important data backed up, I would really like to save the rest of it. It ...
0
votes
4answers
7k views

Usb flash drive (no media) - how to format?

I'm using Kali Linux x64 2017. When I insert USB flash drive (16 GB) computer can't recognize it. I want to format it and erase all data. I've already tried on Windows and the problem is same (usb ...
5
votes
1answer
727 views

Why 576GB of files on ext4 doesn't fit on a 600GB xfs? [closed]

I want to test XFS dedup feature, so i put a new HD to my fileserver VM. I started rsync files from old disk to new one, but I got "No space left on device". This is my df -h output: Filesystem ...
0
votes
1answer
423 views

df from busybox shows different number of inodes than that of tune2fs

we have Beaglebone black based custom board, we have busybox shell including coreutils. busybox version is BusyBox v1.20.2 (2017-10-16 16:39:36 EDT) now we wanted to check the inode usage in each ...
-2
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1answer
270 views

Compile a kernel using a custom file system type such as “myext4”

Is it possible to take the source code of ext4, make no changes to it apart from changing its name to "myext4" and then compiling my kernel so that it accepts this custom file system type? Is it as ...
3
votes
1answer
519 views

ext4 : bad block fixed, but is this disk dying?

Ubuntu 17.04; ext4 filesystem on 4TB WD green SATA [WDC WD40EZRX-22SPEB0] Mount (on startup, from fstab) failed with bad superblock. fsck reported / inode damaged, but repaired it. 99% of files ...
1
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1answer
1k views

Disable and enable ext4 journaling ?

If I disable the journaling function of an EXT4-filesystem using the command tune2fs -O ^has_journal /dev/sda and enable it after the next start, will the data saved on the harddisk remain unaffected ...
2
votes
1answer
12k views

How to clear ext4 filesystem of partition in arch

I'm installing Arch Linux by guide and misinterpreted some stuff about installing the bootloader. Therefore I went back and cleared my /dev/sdb partitions. Before that I made sdb1 as linux filesystem (...
3
votes
1answer
270 views

Constant low volume writes to raid array (jbd2), what's causing it?

I have a raid array, in fact, two raid arrays which are very similar, however one is being written to constantly (by jbd2 it seems) and the other is not. Here are the arrays: md9 : active raid5 sdl4[...
14
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4answers
7k views

Does any file system implement Copy on Write Mechanism for CP

We have seen OS doing Copy on Write optimisation when forking a process. Reason being that most of the times fork is proceeded by exec , so we don't want to incur the cost of page allocations and ...
1
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0answers
2k views

undelete 1 file from ext4 on LVM on LUKS

summary How to (relatively painlessly and reliably) {restore, undelete} a file from an ext4 filesystem inside a LVM volume inside a LUKS container, given one knows the fully-qualified path to the ...
3
votes
1answer
840 views

linux: touch date precision

On my linux system if I display the current date "t1", touch a file "f" then display the modification time "t2" of that "f" I would expect t1 < t2. But that's not what I always get when I execute ...
6
votes
1answer
5k views

“inode extent tree (at level 1) could be shorter IGNORED”

I have a Debian system here. fsck runs from time to time while booting (on an ext4 file system). I get messages like this: inode extent tree (at level 1) could be shorter IGNORED What do they mean?
5
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1answer
281 views

What are costs of storing xattrs on ext4, btrfs filesystems?

I imagine that adding n xattrs of length l of to f files and d directories may generate costs: storage path resolution time / access time ? iteration over directories? (recursive find over (fresh ...
2
votes
2answers
4k views

What does this mkfs.ext4 operand mean?

I am using GParted (0.28.1, Fedora 25) to format a external drive and noticed that the command displayed is: mkfs.ext4 -F -O ^64bit -L "INSTALL" /dev/sdd1 When making disks in the past from command ...
5
votes
4answers
3k views

How come that inodes of directories store filenames in ext4 filesystem?

A directory inode isn't substantially different from that of a regular file's inode, what I comprehend from Ext4 Disk Layout is that: Directory Entries: Therefore, it is more accurate to say ...