ext4 (fourth extended filesystem) is a journaling file system for Linux, developed as the successor to ext3.
25
votes
6answers
2k views
How do I know if a partition is ext2, ext3, or ext4?
I just formatted stuff. One disk I format as ext2. The other I want to format as ext4. I want to test how they perform.
Now, how do I know the kind of file system in a partition?
17
votes
4answers
13k 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 ...
13
votes
2answers
360 views
Can the same ext4 disk be mounted from two hosts, one readonly?
I know that mounting the same disk with an ext4 filesystem from two different servers (it's an iSCSI vloume) will likely corrupt data on the disk. My question is will it make any difference if one of ...
11
votes
1answer
990 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 ...
10
votes
2answers
2k 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 :).. ...
9
votes
2answers
1k views
Is it possible to change Inode count on an ext4 filesystem? [duplicate]
Possible Duplicate:
How can I increase the number of inodes in an ext4 filesystem?
I have a homemade NAS with Debian Wheezy 64bit. It has three disks - 2x2TB and 1.5TB, pooled together ...
8
votes
1answer
918 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?
...
8
votes
1answer
954 views
Birth is empty on ext4
I was just reading up on the Birth section of stat and it appears ext4 should support it, but even a file I just created leaves it empty.
~ % touch test ...
8
votes
1answer
2k 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 ...
7
votes
3answers
7k 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 ...
7
votes
1answer
403 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?
7
votes
1answer
252 views
How can I mount filesystems with > 4KB block sizes?
I have a 3TB hard disk pulled out of a WD Mybook Live NAS. The partition table is as follows:
Model: ATA WDC WD30EZRS-11J (scsi)
Disk /dev/sdb: 3001GB
Sector size (logical/physical): 512B/4096B
...
7
votes
2answers
14k 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 ...
7
votes
1answer
1k 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 ...
6
votes
5answers
2k 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 ...
6
votes
1answer
666 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) ...
6
votes
1answer
486 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 ...
6
votes
1answer
135 views
ext4: where did my free space go?
I just upgraded my Mageia 2 64bits VM to Mageia 3, and now my virtual disk free space is almost nil, even though less than 100% of the space is used.
I am not an ext4 filesystem expert but I have ...
6
votes
1answer
4k 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
3answers
446 views
ext2/3/4 reserved blocks percentage purpose
I know that this feature dates back 20 years but I still would like to find out
What is the purpose of the reserved blocks in ext2/3/4 filesystems?
5
votes
2answers
1k 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 ...
5
votes
2answers
333 views
Defragging an ext partition?
Why don't ext2/3/4 need to be defragmented? Is there no fragmentation at all?
5
votes
1answer
1k views
largefile feature at creating file-system
Is useful to use -T largefile flag at creating a file-system for a partition with big files like video, and audio in flac format?
I tested the same partition with that flag and without it, and using ...
5
votes
2answers
3k 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 ...
5
votes
1answer
2k 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 ...
5
votes
1answer
755 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 ...
4
votes
2answers
3k 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
1answer
185 views
Why could the size of the “dot file” /. exceed 4096?
Today I found an "empty" directory with a size of 4MB.
It had no visible contents, so I tried ls -lah. This showed me some hidden files (not very large). Searching for the reason why the directory ...
4
votes
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? ...
4
votes
1answer
105 views
ext4 directory lists as a file
I'm working with a large (8TB) EXT4 filesystem in linux. After a power outage, the filesystem wouldn't mount. fsck is taking weeks to complete, but i ran testdisk and i'm able to see my partition ...
4
votes
2answers
423 views
Recovering an ext4 filesystem with corrupt journal
I have a hard drive that seems to have developed some kind of hardware problem in the journal. This prevents the drive from being loaded. Running mount -r -t ext4 /dev/sda5 /mnt/root results in the ...
4
votes
2answers
3k 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 ...
4
votes
1answer
171 views
Is it possible to disable file permissions on a ext3 or ext4 file-system?
Is it possible to disable file permissions on an ext3/4 file-system?
Just wondering if it's possible to completely disable or ignore file permissions on a ext3 or ext4 file system. Perhaps a mounting ...
4
votes
1answer
192 views
What are EXT4 Security Labels?
During Gentoo installation of Gnome keyring, I am told to switch on EXT4 Security Labels, which is described in the kernel documentation by:
Security labels support alternative access control ...
4
votes
1answer
1k 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 ...
4
votes
1answer
2k 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 ...
3
votes
6answers
12k 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 ...
3
votes
1answer
383 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
3answers
73 views
Convert old /home from ext3 to ext4
I have an old /home partition, that dates back to former linux systems, and it is still in ext3 format. Whereas the rest of my system, / and some other mounted point are devices formated in ext4.
I ...
3
votes
3answers
922 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 ...
3
votes
2answers
2k 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 ...
3
votes
1answer
549 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 ...
3
votes
3answers
319 views
A lot of errors on ext4, however smart doesn't show any errors
I have a Debian box with additional ( it is not a system disk ) 1.5Tb sata hdd (wd caviar green). There is only one partition on the whole disk.
Disk is used for backups from remote system (with ...
3
votes
1answer
3k 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 ...
3
votes
2answers
231 views
Fastest way to get list of all file sizes
I'm trying to create a graph of the distribution of file sizes on my ext4 system. I'm trying to write a script to scrape this information from my computer somehow. I don't care where the files are ...
3
votes
1answer
183 views
corrupted library after hard shutdown
yesterday night my laptop executes a hard shutdown because my battery was out of charge. After the reboot Xorg hangs and the troubleshooting was pretty hard. A first file system check of my ext4 ...
3
votes
1answer
1k views
recovering ext4 partition after dd'ing over start of HD
I accidentally used dd and wrote over the first 208MB of my external disk. What I wrote over is a partition on its own (Debian nestinstaller) so what I see now is not my old (now damaged) ext4 ...
3
votes
2answers
240 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 ...
3
votes
1answer
931 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
1answer
410 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 ...
