Tagged Questions

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

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2answers
1k views

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.
1
vote
1answer
8k views

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 ...
4
votes
1answer
3k views

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 ...
3
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1answer
6k views

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 ...
10
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1answer
2k views

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? ...
13
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1answer
2k views

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 ...
1
vote
3answers
661 views

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.
6
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1answer
6k views

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 ...
5
votes
1answer
4k views

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 ...
2
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0answers
882 views

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 ...
6
votes
1answer
734 views

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 ...
3
votes
2answers
1k views

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 ...
13
votes
7answers
49k views

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 ...
22
votes
4answers
38k views

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 ...
3
votes
3answers
2k views

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 ...
5
votes
2answers
4k views

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 ...
3
votes
3answers
836 views

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 ...
5
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2answers
4k views

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 ...
6
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1answer
1k views

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) ...
5
votes
1answer
1k views

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 ...
3
votes
1answer
791 views

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 ...
3
votes
2answers
324 views

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 ...
6
votes
3answers
7k views

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 ...
10
votes
1answer
4k views

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 ...
5
votes
1answer
3k views

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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4answers
22k views

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 ...
2
votes
1answer
718 views

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 ...
4
votes
1answer
1k views

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 ...
3
votes
2answers
1k views

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 ...
7
votes
1answer
2k views

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 ...
2
votes
2answers
3k views

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. ...
4
votes
2answers
4k views

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 ...
4
votes
2answers
4k views

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 ...
8
votes
3answers
12k views

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 ...
10
votes
2answers
3k views

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 :).. ...
3
votes
1answer
453 views

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 ...
7
votes
6answers
3k views

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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2answers
3k views

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. ...
3
votes
2answers
3k views

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 ...
8
votes
1answer
491 views

Can I convert an ext3 partition into ext4 without formatting?

my home directory is on a separate partition which still uses ext3. Is there a way to convert this partition into ext4 in a non-destructive way?
6
votes
2answers
390 views

Defragging an ext partition?

Why don't ext2/3/4 need to be defragmented? Is there no fragmentation at all?
4
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2answers
2k views

what is commit=0 for ext4? does mdadm not support it?

I see this in my dmesg log EXT4-fs (md1): re-mounted. Opts: commit=0 EXT4-fs (md2): re-mounted. Opts: commit=0 EXT4-fs (md3): re-mounted. Opts: commit=0 I think that means that dealloc is disabled? ...