The ext4 or fourth extended filesystem is a journaling file system for linux/*nix developed as the successor to ext3.

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4answers
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is there such a thing as a 'quick' format for ext4?

in Windows it's very fast to format with NTFS. I have a low powered Linux machine, with little RAM. formatting a 2TB volume to ext4 takes a long long time is there anything I can do to speed up ...
2
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2answers
7k views

Does CentOS 5.x support ext4?

I believe the default OS file system in CentOS 5 is ext3. Is it possible to use ext4 on Centos 5.x, or only on 6.x? Can I upgrade an existing ext3 filesystem to ext4?
15
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4answers
706 views

Ensuring a repeatable directory ordering in linux

I run a hosted continuous integration company, and we run our customers' code on Linux. Each time we run the code, we run it in a separate virtual machine. A frequent problem that arises is that a ...
0
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1answer
346 views

Linux Container conversion to Vagrant and back

The situation is the following: we have an lxc (linux-container), which contains a Debian Squeeze distribution, built up with a preseed file. We wanted to add some extra packages (packages for the OMF ...
6
votes
2answers
6k views

Best options to create and mount an ext4 volume containing > 10M files in one directory

What are the appropriate options to mkfs and mount for an ext4 filesystem with a folder containing >10 million files for read access? What I have so far: umount /media/dirsizetest mkfs.ext4 -L ...
3
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3answers
1k views

Journaled filesystems and power failure

I heard that even a journaled filesystems such as EXT3/EXT4 might corrupted during power failure, e.g. from wikipedia [1]: In the event of a system crash or power failure, such file systems are ...
1
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3answers
4k views

Possible to mount an ext4 partition image via FUSE?

I'm attempting to mount an ext4 partition image in userspace. (no sudo, no special config/permissions modification to /dev/loop0 or /etc/fstab etc). So I'm hoping FUSE will come to the rescue. ...
4
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1answer
2k views

Linux ext4 “extents” attribute

I noticed the e attribute on several files/directories on Linux machines installed on ext4 filesystems. [kelly@p2820887.pubip.serverbeach.com ~]$ lsattr -d /bin -------------e- /bin According to ...
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0answers
863 views

ext4 loopback device, Buffer I/O Error on reboot

I am trying to mount a loopback device on my ext4 formatted ssd drive. I get these errors when I reboot on Linux kernel 2.6.38.8 Buffer I/O error on device loop1, logical block 0 Here is what I do: ...
7
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2answers
19k views

ext4 file-system max inode limit - can anyone please explain?

Recently we had a problem where one of the ext4 file-systems seemed unable to handle very large number of files, more than 6mln in this case, in spite of having enough space. Is it 6mln the max ...
-3
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1answer
674 views

12.04 ext4 - cannot create regular file/No space left - with a lot of space and inodes

This seems similar: EXT4 "No space left on device (28)" incorrect but there is no explanation I created an ext4 filesystem on a RAID 1 array with: mke2fs -t ext4 -T small /dev/md0 ...
3
votes
3answers
977 views

different uuid from blkid and tune2fs

I copied (dd) a partition from /dev/sdb3 (GPT partition) to /dev/vg0/lv0_sys (lvm2 lv) Sure to be required to adjust the uuid on one of them, I found that blkid shows me two different uuid's for the ...
1
vote
3answers
935 views

Can ext4 fs be completely unrecoverable broken due to power loss while disk is writing?

Suppose you are doing a full speed write to disk in a linux pc box with ssd or mechanical disk (OS also on the same disk, there is no battery/UPS): cat /dev/urandom > omg.txt If the power losses ...
1
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0answers
539 views

Heavy disk write on a Debian VPS gives “ata1: lost interrupt (Status 0x50)”

I have a new Debian VPS that appears to fail almost every time I run a heavy disk write test on ext4 filesystem. The filesystem goes to read-only mode and "ata1: lost interrupt (Status 0x50)" is ...
1
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2answers
1k views

CentOS: Set number of inodes in ext4 on Install

During installation of CentOS 6 I would like to set the number of inodes created on the ext4 partitions. Is there a way to do this? I have been unable to locate a solution. Example use case: I know ...
3
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5answers
6k views

EXT4 “No space left on device (28)” incorrect

I have been through the other questions/answers regarding inode usage, mounting issues and others but none of those questions seem to apply... df -h /dev/sdd1 931G 100G 785G 12% ...
1
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2answers
1k views

Limit total size of a directory in linux

I have a service daemon that creates a lot of temp files. Recently my server died, because a malicious user managed to flood /tmp and fill up the disk. I have taken some measures to actively clean up ...
2
votes
2answers
286 views

Does dm-crypt support journaling filesystem transactional guarantees?

I'm considering using ext4 on encrypted LVM (which uses LUKS and dm-crypt). Will the transactional guarantees in ext4's journaling be preserved? Bonus: where may I find authoritative information ...
1
vote
2answers
863 views

bind (hardlink) one directory to many places

I need to "bind" one directory to many chrooted places. I know that I can do "mount -o bind", but this requires special processing on startup each time (run the mount). Is there a way to do it on the ...
2
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1answer
4k views

MySQL is VERY slow on my ext4 file system [closed]

I have a normal hardware, I just installed Ubuntu 11.04 anew. But something's completely wrong. PHPunit tests are REALLY slow. I have no idea what's wrong. With ext3 all was normal. Thanks.
1
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0answers
392 views

e2fsck miserably aborts: memory allocation failed on 64 bit OS and scratch directory

After an unsuccessful Virtualbox VDI drive resize following the instructions here, the primary ext4 partition became of unknown type. I fixed this with testdisk and then boot-repair, which made it be ...
3
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3answers
2k views

RAID6 mdraid -> LVM -> EXT4 root with GRUB2?

2012-03-31 Debian Wheezy daily build in VirtualBox 4.1.2, 6 disk devices. My steps to reproduce so far: Setup one partition, using the entire disk, as a physical volume for RAID, per disk Setup a ...
1
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2answers
408 views

Relabeling of filesystems (SELinux) fails

After compiling the policy modules and re-compiling my core packages (Gentoo 32bit) I wanted to relabel the filesystems (via rlpkg -a -r) and packages but I get these error messages: Relabeling ...
0
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1answer
166 views

Trade reliability for speed in a slow filesystem

On my box running Ubuntu Server 11.10 I have a rather slow soft RAID6 array on four USB sticks (and no other means for persistent storage). I want a faster filesystem on that box. I'm OK if I'd lose ...
0
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2answers
1k views

ext4 filesystem broken

I have a synology nas with an internal hdd (a 2TB wd ears). This drive has SMART errors. I took the drive and build it in a external USB case. Then i booted Linux mint and tried to mount the data ...
5
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2answers
1k views

PERC 6/i | ext4 | raid5 | 4 disks - improve write performance

I am running several fileservers using this controller, filesystem and disk setup. All of them are suffering from poor write performance, once the 256MB BBU Write Cache is full i get really high ...
0
votes
3answers
772 views

How many subdirectories does the XFS filesystem support within a given directory?

EXT3 supports 32,000 subdirectories. EXT4 supports 64,000... I've read about people having millions of subdirectories on the XFS filesystem, but can't find an exact value referenced anywhere. How ...
10
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10answers
950 views

How does the number of subdirectories impact drive read / write performance on Linux?

I've got an EXT3 formatted drive on a Linux CentOS server. This is a web app data drive and contains a directory for every user account ( there are 25,000 users ). Each folder contains files that ...
0
votes
1answer
153 views

Problems with degraded RAID arrays

My Ubuntu backup server was recently upgraded in storage space to a RAID 10 array... now it consists of 8T of raw drive space which was before 2T of space. But I have been having trouble when it ...
17
votes
4answers
4k views

“safe” ext4 configuration for systems running unattended

I have a system running linux that must run unattended for long periods of time. The system uses industrial CF card for storage. Most of the time there are no writes to flash, although every now and ...
1
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1answer
565 views

Iozone record sizes and real-life purpose

I am puzzled about Iozone record sizes. My questions are: how to find out what record size my application uses?; what is the correlation between Iozone record size and the filesystem Block Size?; ...
1
vote
1answer
1k views

EXT3 vs EXT4 vs XFS

Recently I read a lot about "new" file systems. I checked some benchmarks that show MySQL working faster on EXT4 or XFS (and some other FS). I also "found" that XFS and EXT4 are included in CentOS ...
7
votes
1answer
2k views

Whats “Birth” field in stat command output

I'm using Fedora-16 with ext4.Suddenly with stat command I can see something called "Birth". # stat history_file1.txt File: `history_file1.txt' Size: 8944 Blocks: 24 IO ...
1
vote
1answer
417 views

On-line backing up Xen virtual machines running on Ext4fs

What methods exist for backing up Xen virtual machine contents? I have some virtual servers running on LVM / Ext4 disks. Preferably a method which can be directly executed over SSH / network ...
2
votes
1answer
1k views

Proper way to remap a partition to a new disk?

I currently run a webserver running Debian. I have a 1GB disk with a single ext4 partition mapped to / and an 8GB disk with a single ext4 partition mapped to /var/www. The 1GB disk is at 70% full ...
13
votes
3answers
4k views

max files per directory in ext4

I manage an application that contains a filestore in which all the files are stored with the filenames equal to their md5 sums. All files are stored in one directory. Currently there are thousands, ...
2
votes
1answer
1k views

Turn off write barriers on ext4 whiche FS is mounted

I am doing some IO intensive DB imports that run for several days now and the IO performance has dropped tremendously over times. The DB data files (log files) are on an ext4 formatted logical volume ...
3
votes
2answers
5k views

ext4 filesystem corruption — maybe hardware error?

I'm getting these errors in dmesg after about half an hour after I turn on the computer: [ 1355.677957] EXT4-fs error (device sda2): htree_dirblock_to_tree: inode #1318420: (comm updatedb.mlocat) ...
2
votes
1answer
3k views

Setting up quotas on 64-bit RHEL6 OS with ext4 filesystem

Setting up a new 64 bit RHEL 6 server with ext4 FS. Have only worked with ext3 and 32bit RHEL5 before. No matter what I try, I cannot get it to work. Current settings for mount (from "mount" ...
2
votes
4answers
2k views

Store and backup 200 million small files

My disk are 10x1TB SAS 7200 RPM in a RAID 10 with a MegaRaid 9260 hardware controller with cache/BBU. This results in a 4.6TB RAID 10 volume. hdparm -t (when device is empty) results in 500MB/s. RAID ...
5
votes
1answer
1k views

5.5GB written daily to 1.2GB root volume - 4 times previous levels

Problem: I recently revamped one of my servers, it was tested prior to use, and functions well, however, a few days ago, I noticed approximately 4 times the usual amount of writes to the root volume. ...
0
votes
2answers
3k views

Not able to mount ext4 file-system in Debian Lenny

I am trying to mount ext4 EBS volume in to my EC2 instance in Debian OS, whenever I try to mount I get the following error: mount: unknown filesystem type 'ext4' I googled around and found a ...
4
votes
2answers
2k views

Any way to recover ext4 filesystems from a deleted LVM logical volume?

The other day I had a proper brain fart moment while expanding a disk on a Linux guest under Vmware. I stretched the Vmware disk file to the desired size and then I did what I usually do on Linux ...
1
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2answers
547 views

Fedora: I deleted a log file 32GB big and could not confirm it through “df” command

I am having a disk space problem on the root partition, so I went through unimportant logs and deleted what could be deleted. One of the files "mysql-slow.log" was 32GB big, but when I deleted it, it ...
1
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1answer
538 views

Debian Squeeze using ext4

Does anyone know of any major issues with running debian squeeze using ext4 as the filesystem rather than ext3? Any known performance or corruption problems? I need support for files bigger than ...
5
votes
3answers
2k views

Convert a software raid volume from ext3 to ext4 (or ext2)?

I have an mdadm created software raid volume in my ubuntu linux 11 machine. It is NOT the boot drive. It is a software raid 5 configuration made from 3 large sata drives. When I created it ...
0
votes
3answers
4k views

Convert ext4 partition to NTFS

Is there a tool or command to achieve it? I did some search around here I didn’t find the answer. Is that possible? I must mention that my ext4 drive that I want to convert have data so it must just ...
6
votes
3answers
7k views

df reports wrong free space for an Ext4 partition

My system is CentOS 6 x86_64 with root partition formatted as ext4. df reports around 3Gb as used space: Filesystem 1K-blocks Used Available Use% Mounted on /dev/md1 ...
-1
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1answer
191 views

Help, ive just corrupted my ext4 partition

After troubleshooting problems with my mdadm config and kernel settings for about a week now i got careless and left my data drives plugged in after a successful boot test. i was attempting to change ...
0
votes
2answers
289 views

Convert Ext3 to Ext4 Filesystem failed because I cannot umount drive

I want to convert my Filesystem from Ext3 to Ext4 because of 32000 directory limit of Ext3. But when I want to umount the drive I get this error: umount: /: device is busy umount: /: device is busy ...