ext4 (fourth extended filesystem) is a journaling file system for Linux, developed as the successor to ext3.
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1answer
18 views
How to give Windows partions' file execute permission
I have installed Linux Mint 17 and Windows 8, as dual boot. 500GB hard disk has 5 partitions. Two of them are NTFS and the other 3 are ext4 partitions.
When I log into Windows, I can not see any ...
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2answers
44 views
How to recover NTFS drive formatted in ext4?
I just installed Linux Mint 17 and when it asked me where to install it I selected the option to overwrite the old Mint 14. Previously I had also windows with NTFS partition of 900GB. Not it is all ...
2
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0answers
34 views
How can I capture a consistent snapshot of a directory and all its children?
We have an application that periodically backs itself up to a directory on the local file system. Inside this directory are several more files and directories.
I want to produce a "snapshot" of all ...
3
votes
1answer
35 views
What is the difference between fsck options -y and -p?
The ext2/3/4 filesystem checker has two options that seem to be very similar, -p and -y.
Both seem to perform an automatic repair, but the manpage states that -p can exit when it encounters certain ...
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1answer
49 views
ex4 to btrfs conversion: If I accidentally lose power to the system during the conversion, will I lose the data?
I want to convert the 3TB 80% full ext4 block device into btrfs and I want to estimate the risks involved in the process.
If I accidentally lose power to the system during the conversion, will I ...
1
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0answers
21 views
ext4 to btrfs conversion: Can I pause, reboot the system and then resume the conversion? [duplicate]
I want to convert a rather big ext4 volume into btrfs. How long will the process will take?
7
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1answer
199 views
Is data=journal safer for Ext4 as opposed to data=ordered?
The default journal mode for Ext4 is data=ordered, which, per the documentation, means that
"All data are forced directly out to the main file system prior to its
metadata being committed to ...
2
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0answers
68 views
Mount from auto to manual and changing dir gives errors
I just installed Ubuntu 14.04 and am trying to mount my internal HD to a different location in the /home/username dir (auto-mount mounts it to /mnt/{uuid} )
But I ran into a problem. In Disks, when ...
6
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1answer
352 views
“Converting” a filesystem from ext3 to ext4
I've read on some Q&A on this website that one can "convert" an ext3 filesystem to ext4 without formatting, by issuing
tune2fs -O extents,uninit_bg,dir_index /dev/dev-name
And then running ...
2
votes
2answers
349 views
External hard drive permissions - ext4
I have an external USB 3 disk drive (2TB capacity) that is most likely going to be moved from machine to machine. The disk has a GUID partition table and an ext4 partition. I am unable to write to the ...
3
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2answers
144 views
Large ext4 partition ridiculously slow when writing
We have four identical Linux servers with a large (5T) hard disk partition. We have Scientific Linux with this kernel:
Linux s3.law.di.unimi.it 2.6.32-358.18.1.el6.x86_64 #1 SMP Tue Aug 27 14:23:09 ...
3
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0answers
54 views
Optimal rootflags for rootfs for ext4 file system running on USB thumdrive [closed]
I have made myself a bootable USB Debian 7 thumbdrive, using debootstrap. It boots nicely - but occasionally freezes for a bit. I can see the load average is much higher than the running tasks should ...
3
votes
1answer
58 views
Where does ext4 store directory sizes?
Where does ext4 store directory sizes? Are they stored in the directory inode?
For example, when I run du -h, it returns directories' size instantly, so I don't believe it calculates it at that time.
...
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vote
3answers
130 views
How much storage overhead comes along with cryptsetup and ext4?
I want to encrypt the content of a directory in a container with an ext4 filesystem using cryptsetup. The size of the container should be as small as possible and as big as necessary, because I only ...
5
votes
3answers
93 views
What filesystem metadata operations are actually journaled in ext4 & xfs?
I can't find a simple, straight answer about which filesystem metadata operations are actually persisted to the ext4 & xfs filesystem journals. Note that I am not inquiring about what POSIX ...
2
votes
1answer
101 views
Why does fstrim trim all of the free space on my mdraid mirror after a reboot? [duplicate]
I have a server with 2 SSDs:
Model Family: Intel 520 Series SSDs
Device Model: INTEL SSDSC2BW240A3F
Firmware Version: 400i
User Capacity: 240,057,409,536 bytes [240 GB]
Sector Size: ...
0
votes
2answers
52 views
I accidentally formatted the wrong volume - is it possible to restore the previous Ext4 filesystem?
I know that a similar question has already been asked. This morning I accidentally formatted the wrong volume, containing mostly video files (about 30GB each).
I am currently trying to restore the ...
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1answer
107 views
Best parameters for ext4 filesystem to handle virtualbox disk images
I have ext4 partition, which holds disk image files VirtualBox works with. They all are fixed-size images (i.e. files never change their size). They are defragmented as much as possible (with ...
2
votes
0answers
18 views
ext4 flags to specify “extents” mode?
I've formatted a new filesystem with and without extents feature just to understand how this feature works. However, when I look at the inode field i_flags I see that this field always has zero value ...
4
votes
2answers
106 views
Reliable way to detect ext2 or ext3 or ext4?
I need to detect a filesystem type from a C/C++ program using the filesystem superblock. However, I don't see much differences between superblocks for ext2 and ext4. The s_rev_level field is the same ...
3
votes
1answer
44 views
ext4 inode size, shown by dumpe2fs
Manpage about mke2fs says "mke2fs creates 256-byte inodes by default". I've formatted my small (320MB) test partition with command:
sudo mkfs -t ext4 /dev/sdc1
The defaults for the mke2fs are ...
4
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1answer
220 views
chmod does not change permissions of certain directories
System file: ext4
I changed the owner of files to apache: with the command:
chown -R apache: wp.localhost
Then, I could not change the permissions of directories in wp.localhost nor the ...
1
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1answer
56 views
Why is it impossible to change the inode count of an ext filesystem?
I know that it isn't possible to change the inode count of an ext filesystem after its creation, but I haven't been able to find any explanation on why it isn't.
Can anyone enlighten me?
3
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1answer
69 views
ext4, why 70k file takes 88 blocks
[root@xx]# cat -n create_extents.sh
1 #!/bin/bash
2
3 if [ $# -ne 2 ]
4 then
5 echo "$0 [filename] [size in kb]"
6 exit 1
7 fi
8
9 ...
0
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2answers
46 views
Are there any tools to recover files from a previously formatted WinNT drive?
I scratched the previous Windows NT filesystem, now I'm running Ubuntu. I've created the whole disk as EXT4.
Are there any tools to locate and save some previous Windows files from the original ...
2
votes
0answers
116 views
How to find orphan directory entries in a ext4 disk
This comes from a long story of trying to recovering a TrueCrypt volume from a hardware failure (thanks, WD). I ended up with an unencrypted 3TB image that had the files that I want to recover.
...
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4answers
46 views
targeting a specific block with e2fsck to shorten wait
Recently had a LVM'd CentOS 6.5 install get accidentally cold-shutdown. On bootup, it says that the home partition need fscking:
/dev/mapper/vg_myserver-lv_home: Block bitmap for group 3072 is not ...
0
votes
1answer
62 views
Recovering truncated file
I'm in a peculiar situation. While editing a Perl program I accidentally truncated the file to zero length (using an Emacs lisp code I was developing). I need to recover that program... How do I that ...
1
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1answer
31 views
recovering /home folder from faulty drive
I was going to try ddrescue to recover data from a faulty (beeping) laptop drive and a primary ext4 partition.
Reducing the number of reads from the disk should reduce the recovery time and increase ...
3
votes
2answers
1k views
Fix EXT4-fs bad geometry (block count exceeds size of device)
I have a micro SD card which has a FAT32 partition and an EXT4 partition. The EXT4 partition will no longer mount. dmesg shows the following error:
EXT4-fs (sdb2): bad geometry: block count ...
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0answers
48 views
Optimization for an SSD?
I am running Fedora 20 on a Laptop ( Lenovo Ideapad Yoga 2 Pro ) with an SSD. My filesystem is LVM with ext4 as the format option. I am now running Fedora as the only OS on the system with Legacy BIOS ...
0
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1answer
34 views
mke2fs difference between -i and -I options
sudo mke2fs
Usage: mke2fs [-c|-l filename] [-b block-size] [-C cluster-size]
[-i bytes-per-inode] [-I inode-size] [-J journal-options]
[-G flex-group-size] [-N number-of-inodes]
[-m ...
2
votes
0answers
61 views
Do ext(4?) filesystems intrinsically store newer data in a fashion that is more prone to corruption?
I recently had a corrupted ext4 filesystem throwing these errors:
kubuntu@kubuntu:~$ sudo mount -t ext4 /dev/sdc2 c1
mount: wrong fs type, bad option, bad superblock on /dev/sdc2,
missing codepage ...
3
votes
1answer
833 views
Short read while trying to open partition
On my personal home computer running Kubuntu Linux 13.04 I'm having trouble mounting a partition that is very dear to me. My backup policy is to perform a backup about monthly, so I do have a backup ...
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0answers
72 views
e2fsck -y /dev/sda changed my 6TB disk into 1.8TB
After problems with mount I run e2fsck -y -b BLOCK /dev/sda and it was running for 3 days on 6TB raid 0, when it completed this was the output:
/dev/sda: ***** FILE SYSTEM WAS MODIFIED *****
...
2
votes
1answer
78 views
Same file with different content on every read [closed]
I have a problem with a filesystem here on a storage machine. We noticed, that many of the data that comes out of the systems seams to be corrupt, but only with minor problems like CRC errors with ...
3
votes
3answers
120 views
Ext4 - How to enable extra sanity, checksums, validations, tests of any kind?
I'm running Ext4 on a harddrive, and to be perfectly honest, I don't really trust the drive because it's old and has a few badblocks. I have nonessential data on the drive, so if it died tomorrow, ...
3
votes
1answer
81 views
File containing ext filesystem
Let's suppose I create a file, map it to /dev/loop0, and create a LUKS partition inside
dd if=/dev/zero of=myfile bs=1M count=1000
losetup /dev/loop0 myfile
cryptsetup -c aes-cbc-essiv:sha256 -s 256 ...
1
vote
1answer
163 views
Why is my ext4 filesystem recognizable only on the machine it was formatted on?
Xubuntu liveCD 11.04 running on "bad machine" with mdadm RAID1 array with an unrecognizable ext4 filesystem:
To rescue some files, I installed a new hard drive and formatted it to ext4. I copied ...
3
votes
1answer
93 views
Something like VMware “Changed Block Tracking” (CBT) in linux
I'm wondering if is there any possibility to track changed blocks in linux with an ext3/ext4 filesystem (or a specific one supporting it).
I mean a feture like the Changed Block Tracking (CBT) ...
2
votes
2answers
463 views
How to clean journals in ext3/ext4 filesystem? [closed]
Some preamble: I'm taking bitwise copy of disk devices (via dd command) from twin hosts (i.e. with the same virtualized hardware layout and software packages, but with different history of usage). To ...
3
votes
1answer
144 views
zerofree verbose returns what?
zerofree -v /dev/sda1 returned
123642/1860888/3327744.
The man page does not explain what those numbers are:
http://manpages.ubuntu.com/manpages/natty/man8/zerofree.8.html
I found some code on ...
3
votes
1answer
232 views
“unknown partition table” - misconfigured kernel
I was compiling a custom linux kernel for a newly installed machine, and after booting into the new kernel (3.12), the init process fails to find a root device, which I traced to the system getting an ...
0
votes
1answer
67 views
e2fsck giving some error
I am playing with LVM and while doing lvreduce. I now get this error:
[root@localhost raja]# e2fsck -f /dev/vg1/lvol2
e2fsck 1.41.12 (17-May-2010)
e2fsck: Superblock invalid, trying backup blocks...
...
4
votes
1answer
223 views
How can I dump the contents of a filesystem's superblock?
I understand that I can list the location of a filesystem's superblocks using the following commands.
Example
First get the device handle for the current directory.
$ df -h .
Filesystem ...
2
votes
0answers
105 views
jbd2 journal constant i/o
iotop reports a constant i/o about 3% of [jbd2/vda1-8], I think this is the journal manager for ext4.
my fstab is:
UUID=X / ext4 defaults,noatime,nodiratime 1 1
tmpfs /dev/shm ...
2
votes
4answers
540 views
How do I find the offset of an ext4 filesystem?
I have a failing hard drive that is unable to write or read the first sectors of the disk. It just gives I/O errors and that is all there is. There are other areas on the disk that seem (mostly) fine.
...
2
votes
2answers
870 views
After crash, e2fsck fails with weirdly high block numbers/sizes
After a breaker trip a Raspberry Pi of mine started to halt boot with kernel panic (same message as here). This is a Raspberry Pi running Raspbian, so it runs from a SD card, from a main ext4 ...
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2answers
249 views
How can I fill the free space with zeroes in Ubuntu 12.04 (ext4)?
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 (2TB). The size of this vhd is 360 GB. But the real size is about ...
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0answers
88 views
livecd-tools - ext4 errors
I'm using livecd tools to build an ISO image customized to my liking. It appears to build fine, but after booting up, I get a bunch of ext4fs errors indicating referenced inodes were deleted. My ...
