Questions tagged [ext4]

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

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How to extend an ext4 partition and filesystem?

I have a 400GB disk with a 320GB ext4 partition. I would like to grow the ext4 partition to use the left space (80GB of free space). +--------------------------------+--------+ | ext4 ...
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64 votes
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Is it possible to on-line shrink a EXT4 volume with LVM?

Today I tried this on my machine with OpenSUSE 12.3 (kernel 3.7): # resize2fs /dev/mapper/system-srv 2G resize2fs 1.42.6 (21-Sep-2012) Filesystem at /dev/mapper/system-srv is mounted on /srv; on-line ...
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46 votes
3 answers
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What is the maximum number of files a file system can contain?

Given the current structure of a directory entry on a ext4 file system on Ubuntu, what is the maximum number of files a file system can contain? What is the general method of calculating the maximum ...
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43 votes
5 answers
72k views

Ext4 vs. XFS vs. Btrfs vs. ZFS for NAS [closed]

My use case: I have Ubuntu Server 18.04 installed on an M.2 SSD. I have a 4TB HDD I want to add as storage. Since it's mostly for large media files and backups, it won't be written to very often. ...
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Why does deleting a big file take longer?

My understanding is that running rm on a file simply unlinks it, marking the space as free in the filesystem. It should then follow that deleting one file always takes roughly the same amount of time (...
Tom Marthenal's user avatar
34 votes
4 answers
75k views

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 the ...
stuck's user avatar
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30 votes
2 answers
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Transparent compression filesystem in conjunction with ext4

I am trying to test a project that needs compressed storage with use of the ext4 file system since the application I use relies on ext4 features. Are there any production/stable solutions out there ...
user235918's user avatar
26 votes
12 answers
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Storing and backing up 10 million files on Linux

I run a website where about 10 million files (book covers) are stored in 3 levels of subdirectories, ranging [0-f]: 0/0/0/ 0/0/1/ ... f/f/f/ This leads to around 2400 files per directory, which is ...
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23 votes
6 answers
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How to clean up an unprocessed orphan inode list?

I tried to mount a formerly readonly mounted filesystem read-writeable: mount -o remount,rw /mountpoint Unfortunately it did not work: mount: /mountpoint not mounted already, or bad option dmesg ...
bmk's user avatar
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22 votes
4 answers
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"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 ...
Grodriguez's user avatar
21 votes
7 answers
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Which filesystem for large LVM of disks (8 TB)?

I have a Linux server with many 2 TB disks, all currently in a LVM resulting in about 10 TB of space. I use all this space on an ext4 partition, and currently have about 8,8 TB of data. Problem is, I ...
alphatiger's user avatar
21 votes
6 answers
45k views

exportfs: Warning: /home/user/share does not support NFS export

'exportfs -r' returns me this error when I'm trying to export /home/user/share (ext4): exportfs: Warning: /home/user/share does not support NFS export. /etc/exports: /home/user/share 192.168.1....
Talis's user avatar
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19 votes
3 answers
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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 number,...
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18 votes
8 answers
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Is btrfs production ready?

I've seen a lot of information on btrfs lately. I have been considering ext4 for my next filesystem, but am tempted by btrfs instead. How widely used is btrfs? What are the pro's and con's?
mdpc's user avatar
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Is there a way to protect SSD from corruption due to power loss?

We have a group of consumer terminals that have Linux, a local web server, and PostgreSQL installed. We are getting field reports of machines with problems and upon investigation it seems as if there ...
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18 votes
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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 ...
Paul Biggar's user avatar
18 votes
4 answers
16k views

How to get checksum data integrity on ext4?

On file systems like btrfs you can preform a scrub, which will go though all the data to see if the data still matches the file system checksum. I would like to check the data on ext4 if it is ...
Sandra's user avatar
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17 votes
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ext4 listing of files very slow in one specific directory that contained lots of files before

Background I had a small logrotate misshap... Logrotate would rotate the archived logs by misstake causing a quadratic growth of files in my /var/log/. And by the time I caught wind that something ...
Emma's user avatar
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16 votes
4 answers
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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, ...
Jeroen Ooms's user avatar
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Production-ready, highly reliable filesystems on Linux: ext4 ext3 XFS or JFS (or ZFS)?

The last real question I've seen on this topic is from about two years ago (is ext4 ready for production usage). In the intervening time, how has ext4 improved? XFS, JFS, and ext3 are the standby ...
warren's user avatar
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15 votes
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Which "features" of ext4 existing ext4 partition uses?

When I create ext4 filesystem, there are many "features", which I can enable and disable - like has_journal, extent, huge_file and so on. Is there any way to know, which options were used while ...
Alexey Chernikov's user avatar
15 votes
6 answers
32k views

What are the differences between ext3, ext4 , ReiserFS?

And why should I pick one instead of the other?
Andrea Ambu's user avatar
15 votes
4 answers
16k views

Linux: Why change inode size?

Tune2fs allows to change inode size from default (128 bytes on ext3, 256 bytes on ext4) to almost anything, but it should be power of two. What are the reasons for changing default inode size? Here ...
Vladislav Rastrusny's user avatar
14 votes
6 answers
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Is the F.U.D. about ext4 justified? Or would it be safe to use in some production systems?

I am wondering if ext4 is safe to use on my servers. But I've heard so much FUD about it that I am concerned. Our system could lose some data, and it would not be too big a deal. Even a full days ...
Stu Thompson's user avatar
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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 Block:...
webminal.org's user avatar
13 votes
4 answers
3k views

How to delete millions of files without disturbing the server

I'd like to delete an nginx cache directory, which I quickly purged by: mv cache cache.bak mkdir cache service nginx restart Now I have a cache.bak folder which has 2 million files. I'd like to ...
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13 votes
2 answers
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Performance impact of running different filesystems on a single Linux server

The book "HBase: The definitive guide" states that Installing different filesystems on a single server is not recommended. This can have adverse effects on performance as the kernel may have to ...
Alex's user avatar
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12 votes
3 answers
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disk space overhead in ext4

I'd like to know if there's some rule (or formula) I can apply to find out how much of disk space will be used by the filesystem in an ext4 partition. for example, in a partition of 100 GB, how much ...
cd1's user avatar
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12 votes
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Ext4 usage and performance

I've got a cluster of machines running Carbon and Graphite that I need to scale for more storage, but I'm not sure if I need to scale up or out. The cluster is currently comprised of: 1 Relay Node: ...
Sammitch's user avatar
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12 votes
2 answers
20k views

How to hot backup/snapshot an ext4 partition (in the absence of LVM)?

I'm currently tasked with bringing up a existing server to (at least more) professional standards - with as little disruption as possible to end-users. To have a proper rollback, I need to backup the ...
Roman's user avatar
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11 votes
10 answers
5k 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 ...
T. Brian Jones's user avatar
11 votes
5 answers
11k views

Recovering a file with bad blocks in the middle

A large file on our ext4 file system may have picked up a bad block in the middle. Copying the file to another drive results in an input/output error part way through. Data beyond the bad sectors ...
Chris C.'s user avatar
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11 votes
3 answers
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fsck.ext4: How to force to check the whole file system?

It seems fsck.ext4 quit very soon, I guess it only checks the journal logs, and do nothing if the journal is clean. Is it? How to force it to check the whole file system? I've tried the -f option, but ...
Lenik's user avatar
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11 votes
6 answers
17k views

How can I compact the VHD file with Ubuntu?

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. I want to compact this VHD (The real size is 50 GB, 360 GB on the ...
AmShegar's user avatar
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11 votes
1 answer
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Linux ext4 "extents" attribute

I noticed the e attribute on several files/directories on Linux machines installed on ext4 filesystems. [[email protected] ~]$ lsattr -d /bin -------------e- /bin According to ...
tylerl's user avatar
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11 votes
4 answers
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SSD TRIM (discard) problems with ext4 on Crucial C300 SSDs with CentOS 5.5

Playing around with using a modern kernel (2.6.37 currently) on an older OS (CentOS 5.5) so we can get TRIM (discard) working on our SSDs (Crucial C300s). The most recent hdparm (9.37) concurs that ...
Don MacAskill's user avatar
11 votes
1 answer
28k views

How can I recover an ext4 filesystem corrupted after a fsck?

I have an ext4 filesystem on luks over software raid5. The filesystem was operating "just fine" for several years when I was beginning to run out of space. I had a 9T volume on 6x2T drives. I began ...
Regan's user avatar
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10 votes
5 answers
4k views

Is ext4 ready for a production usage?

What do you think about ext4 filesystem in the production enviroment ? We are very close to launching our project that will use tens of millions quite often updated not very big files and we need to ...
Konstantin's user avatar
10 votes
6 answers
4k views

Options for performance improvements on very big Filesystems and high IOWAIT

I have a Ubuntu 16.04 Backup Server with 8x10TB HDD via a SATA 3.0 Backplane. The 8 Harddisks are assembled to a RAID6, an EXT4 Filesystem is in use. This Filesystem stores a huge amount of small ...
t2m's user avatar
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10 votes
4 answers
27k 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 ...
Alex's user avatar
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10 votes
1 answer
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Remount root RW without reboot

Today I did something stupid on production xen vm server. I mounted the external device mapper as read only to make a copy of the filesystem. This process went well but then the rootfs / become read-...
posixcompliant's user avatar
10 votes
1 answer
4k views

EXT4 performance has become really bad on system with lots of small files

I have a small embedded device that has only 128MB of RAM attached to this device is a 2TB USB2 hard disk I've been very happy with the performance of the device up until recently when either the ...
stuck's user avatar
  • 707
9 votes
2 answers
9k views

ext4: Running out of inodes [duplicate]

I am running out of inodes. Only 11% available: the-foo:~ # df -i Filesystem Inodes IUsed IFree IUse% Mounted on /dev/mapper/system-home 9830400 8702297 1128103 89% /home Is ...
guettli's user avatar
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9 votes
3 answers
12k views

Causes of sudden massive filesystem damage? ("root inode is not a directory") [closed]

I have a laptop running Maverick (very happily until yesterday), with a Patriot Torx SSD; LUKS encryption of the whole partition; one lvm physical volume on top of that; then home and root in ext4 ...
poolie's user avatar
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9 votes
1 answer
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. ...
cyberx86's user avatar
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9 votes
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Can Btrfs use SSD for metadata and leave bulk data on HDD?

is it possible for Btrfs to use SSD for metadata only & leave bulk data on less costly storage such as HDD? I refered to this page Using_Btrfs_with_Multiple_Devices and can not find a solution. ...
zJay's user avatar
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8 votes
2 answers
6k views

Ext4 partition bigger than 2TB?

Is there a way to make partition bigger than 2 TB on ext4 file system ?? Im trying to do that on debian but get message Partition size can not exceed 2TB ...
B14D3's user avatar
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8 votes
4 answers
19k views

Rsync size is difference from source to destination

I'm using rsync with the options -r for recursive -l copy symlinks as symlinks -t preserve modification time -D preserve devices and specials -v verbose --prune-empty-dirs The source FS is ext4 and ...
lbanz's user avatar
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8 votes
3 answers
57k views

changing filesystem format from xfs to ext4 without losing data

I have a fresh Lucid Lynx (Ubuntu 10.04) running on a laptop. where I defined the filesystems as: mount point / on ext4 (46 Gb) mount point /home on jfs (63 GB) swap as 3 Gb I left the machine over ...
A.Rashad's user avatar
  • 293
8 votes
1 answer
949 views

Linux/ext4/sqlite: Can touching a file while it's being written to cause a race condition?

For context: I need to be able to reliably update the timestamp on some sqlite DB files which get intermittent updates on an ext4 filesystem. Can using the touch command (to update the last ...
Hart Simha's user avatar
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