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

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Can a large number of (small) files degrade the performance of a filesystem?

I'm working on an archival project and currently I'm storing 514600 images (ranging from 200kb to 2mb) on my 4TB NAS drive. The drive itself is formatted as ext4 and I'm writing the files over the ...
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231 views

ext4 superblock backup locations are different from what is documented

When I format an ext4 filesystem the mkfs says: Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000 My sparse_super flag is ...
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56 views

ext4 superblock checksum?

I'm reading the ext4 superblock, but its s_checksum (offset 0x3FC) is always zero. Also the s_checksum_type (offset 0x175) field is zero as well, however according to ...
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1k views

Segmerntation fault when running extundelete on Ubuntu - what to do?

I have a partition raw image on which I am trying to run extundelete to undelete some files from an ext4 filesystem. Unfortunately extundelete exits with a segmentation fault. Is there anything I can ...
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2answers
658 views

Recover Hard Drive Accidentally reformatted from NTFS to Ext4

So me and my friend were installing Arch Linux on my external hard drive. My external hard drive had no data on it, ready to roll. My friend had partitioned my external hard drive (I am positive that ...
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1k views

After deleting lots of large files, free space increases with a large delay

Yesterday, I have deleted 71 GB of files on my home/media server. Free Space before: 117 GB Free space after: 126 GB So, instead of having 71 GB of additional free space, I only had 9 GB. I have ...
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1answer
85 views

Changing fstab options

What happens when file-system options in fstab are changed? Speaking of an already populated file-system, would changing options in fstab cause issues? For example, if one were to enable or disable ...
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465 views

Is ok to limit writes on SSD/EXT4 by setting commit parameter in fstab?

I've installed an SSD on my / (Linux scv 3.8.0-34-generic #49~precise1-Ubuntu SMP Wed Nov 13 18:05:00 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux). If I leave the default settings in /etc/fstab I can see ...
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1answer
2k views

Partition went read-only, how to mount it again?

Every now and then the partition of my Linux installation goes read-only. Since the computer is a laptop, I suppose it's due to some writing error caused by some harsh movement. Partition was mounted ...
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2answers
699 views

Is there anything faster than `find . | wc -l` to count files in a directory?

Not uncommonly I have to count the number of files in a directory, sometimes this runs into the millions. Is there a better way than just enumerating and counting them with find . | wc -l ? Is there ...
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1answer
98 views

ext3 vs ext4 bonnie++ rand/seq create speed

I am testing the difference between ext3 and ext4 for our application. When I run both filesystems through a bonnie++ test, the results for file creation on ext4 aren't very good. While ext3 can ...
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1k views

Shrinking ext4 partition: fdisk won't allow to recreate the partition at the same start block

Last time I shrank a partition, it was just as easy as deleting it and recreating it from the same start sector. But this time, fdisk won't allow to recreate the partition from sector 63, it forces ...
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1answer
2k views

How do I mount vhd disk to Ubuntu (Hyper-V)?

I use windows server 2008r2 with role Hyper-V. The guest system is Ubuntu 12.04 LTC. It is situated on the dynamic virtual hard disk VHD1. I add another VHD2 disk as SCSI. Now I want to mount this ...
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1answer
31 views

EXT and other filesystems

Is it true only NTFS needs to be defragmented? Are filesystems like ext4, 3 and 2 immune to fragmentation issues. Apple never seems to require a defragmentation so what makes some filesystems immune ...
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298 views

Contiguous physical allocation of a set of files in linux filesystem (ext4)

I have a set of files that I wish to be allocated contiguously in the filesystem. I will be accessing all these files sequentially in a single read one after the other and I want to optimize reading ...
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1answer
211 views

EXT4 external hard drive for use with multiple systems

I recently bought a external hard drive to store some data on. I use Linux but I am not a power user. If I format the drive to EXT4, is it possible for the permissions to ever screw up and I lose ...
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1answer
41 views

A file system operation that would incur a seek/rotational cost

I am looking to generate a workload that will do operations on a file system that will make the disk access to have rotational or seeking cost. Env details: partition size: 30 G. File system : ...
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Creating ext4 partition from console

I have a volume /dev/sda1 (1.2 TB) containing an NTFS partition using 0.6 TB space. I want to make an ext4 partition in the remaining 0.6 TB space. I have not tried anything yet because I don't want ...
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3answers
1k views

Moving 2TB (10 mil files + dirs), what's my bottleneck?

Background I ran out of space on /home/data and need to transfer /home/data/repo to /home/data2. /home/data/repo contains 1M dirs, each of which contain 11 dirs and 10 files. It totals 2TB. ...
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2answers
474 views

e2image restore file system metadata

I'm trying to recreate file system metadata on a virtual disk. I can save this metadata using e2image, and the e2image man page tells me I can use e2image -I to restore the file system. Unfortunately, ...
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3answers
365 views

Using ext4 hard drive on Windows XP Pro machine?

Have an old laptop with Windows XP Pro and a new one with Linux Mint 13 LTS. I want to transfer my personal files from the old machine to the new one. Firstly I thought using crossover cable but I ...
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1answer
125 views

Attributes of a file - followup for Windows and Linux

I found a question that lists the (quote): attributes are of a regular file (as opposed to a symbolic link, etc.) on Mac OS X with Mac OS Extended (Journaled) (HFS+) Does such a list exist for ...
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How to analyse timestamp in ext4 manually?

I am doing research on Ext4 and I believe I understand the fundamentals of Ext4. Ext4 stores timestamps. In my assignment, I have proposed to analyse the timestamp of Ext4 MANUALLY instead of typing ...
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Ubuntu 12.04/xp dual boot testdisk wrote the wrong mbr to my storage disk

Using disk Utility in Ubuntu 12.04, I inadvertently formatted my 1TB ext4 storage disk to NTFS. I was in the process of doing clean installs so I just pulled the drive and set up a usb hdd dock to ...
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Will a EXT4 Samba Share be readable by Windows/Mac OS X users?

If I share my ext4 drive by SMB will a Windows/OSX user be able to read/write to it WITHOUT installing additional drivers to their machine?
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717 views

Recover Linux ext4 partition formatted(erased) to hfs+

I have a Linux partition with ext4 and I accidentally formatted it with Mac OS X Disk Utility to HFS+ (Mac OS X Extended Journaled). I tried to recover it with http://www.r-studio.com/ on Windows but ...
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2answers
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stat and ls show wrong file size (terabytes wrong)

Ok, I have a bunch of vCard files, all about 200 to 300 Bytes in size. While trying to get them archived, I wondered why that takes so long and discovered that there is one file with a wrong size. ...
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1k views

eMMC Standards and File System support

I am looking into Android secure erase functions and realized a few things: Android uses eMMC as its storage media, eMMC standards are set by the JEDEC organization (currently most of the ...
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1answer
225 views

Rescue data from ext4 ISO image?

so, my SD card got broken and cannot be read completely (escpacially the directory I want to read from has problems). I was able to create an ISO image of the partition using dd but cannot mount it. ...
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1answer
180 views

How does the number of files in the same folder affect I/O performance in an ext4 filesystem

I'm using Kyoto Cabinet (a key-value store) for my project. The specific type of DB I'm using is DirDB which creates a lot of files in a directory to store the key-value pairs. The server I'm running ...
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1answer
2k views

Corrupted linux partition: EXT4-fs error loading journal

I have a Linux partition (Ubuntu 12.10 upgraded to 13.4) on a machine that originally came with Windows 7. Windows 7 was working unusually slow (still is, and was still running slow after ...
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356 views

Linux: Should off-site backups be stored in ext3 or ext4?

We have been using ext3 for Linux server off-site backups. With everything else on CentOS 6 being ext4, I'm wondering if it would be a better idea to also have the off-site backups in ext4 too? The ...
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1answer
510 views

Linux shows several folders with the exact same name

I recently used a mac to copy several files and folders to a USB drive (ext4 through ExtFS), and now in Linux (Xbian) two folders in the root of the drive are shown four times. The output of "ls ...
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2answers
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How do I read the Ext4 partition of my SD card on Windows? [duplicate]

I have a 32 GB SD card with one FAT32 partition and one Ext4 partition. If I mount the SD card to the computer I can read the FAT32 partition in Windows just fine. But how do I read the Ext4 ...
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setting system time at startup from ext4 filesystem

I have a pc with no battery backup and using ubuntu 12.04 with ext4 it will constantly ask me to handle the situation by saying that my superblocks last write is in the future. So I wonder - can I ...
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I have an ext3 iso disk image. Can I use it and write it to a ext4 partition?

Is it possible to do so ? I am migrating to EXT4 because of the SSD drive that has TRIM funtion. I have to have ext4 partion.
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1answer
322 views

populated hard disk partitioning/moving (a lot of operations) [closed]

I have a HHD which is actually a mess. I would like to organize it and exclude some partitions I don't want to use anymore. Positioning the HD partitions beautifully require moving entire partition to ...
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1answer
399 views

ext4 integration in windows 8 - access through explorer

I know there are similar questions; however none I could find that addressed accessing ext4 through explorer, most others simply use a third party application. However, my question is; is there a way ...
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mkfs.ext4 errors

I've just installed Kali Linux and am working with an img file I created from dd (/dev/zero). When I go to do mkfs.ext4 on it, I get mkfs.ext4: Device size reported to be zero. Invalid partition ...
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Is it safe to disable ext4 journaling on root and home partitions?

On my ArchLinux laptop I have / and an ecryptfs encrypted /home partition formatted with ext4. Both contains importand (backuped) data. Is it safe to disable ext4 journaling when partitions contains ...
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1answer
214 views

Weird behaviour on ext4 dd performance test

I'm testing the performance of ext3/ext4 on a raid1 system (but the same goes for a non raid system). The results from bonnie++ give a distorted image because they circumvent the delayed allocation on ...
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2answers
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rm -rf extremely slow & slows down server

I did a rm -rf foldername in an attempt to delete a folder containing 10,000s of 25KB files. Question Why is it taking so long (Almost 30 minutes)? Why did the server became extremely slow, even ...
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255 views

How do I add additional locations to the Windows 7 Recycle Bin Properties?

I have set up a home network with a small file server running Samba. I read on a forum post that by re-mapping a user folder on Windows 7 to a network drive, a reference to that drive will be added ...
0
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1answer
256 views

FreeNAS 8 and ext fs

i'm trying out freenas8 for my personal NAS, i have lots of data that was in an ubuntu server, but somehow i never got the file sharing right. on freenas things just worked. i installed on usb, tried ...
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ext4 on mdadm reverting data

I have a problem with my home server setup. The problem is that sometimes, but really rarely, it reverts (for a lack of a better term) all my data back to an earlier state (somewhere between months ...
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Do ext4 filesystems need to be defragmented?

Do ext4 filesystems need to be defragmented? If so, how do I defragment them? If not, could you post a simple explanation of why they do not need to be defragmented?
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389 views

HDD is preventing ubuntu from installing

I have recently attempted to install ubuntu on my laptop, replacing windows 7. The HDD was working fine with windows 7. On my first attempt to install ubuntu it kept giving me an error that was ...
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Setting up Fedora alongside Windows 8 with special considerations

I've recently found myself much more comfortable using the console and other tools on my Mac than their counterparts with Windows. Specifically, these tools include LaTeX/xindy, emacs and its load ...
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448 views

extundelete does not finish its work

I need to restore a file on sda7 so I remounted ro und startet extundelete manuel@P5KC:~/recovery/RECOVERED_FILES$ sudo extundelete --restore-all /dev/sda7 WARNING: Extended attributes are not ...
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Disable journaling on ext4 filesystem partition

I'm running Linux Mint on an SSD. I've read how one optimization is to disable journaling. However, when I run the command: sudo mke2fs -t ext4 -O ^has_journal /dev/sda1 I get an error saying that ...