ext2 (second extended filesystem) is a file system that was commonly used by the Linux kernel, but has been largely replaced by ext3/ext4.

learn more… | top users | synonyms

1
vote
1answer
61 views

What is the purpose of ext2 dynamic node size?

I've looked in some documentation of ext2 and according to them (see sources) at rev 1.0 it is possible to set the size of the inodes but it doesn't clarify what is the purpose of the extra bytes ...
1
vote
0answers
24 views

How to recover ext2 if all superblocks are gone? [closed]

I have a 120 GB hard drive that consisted of an ext2 partition (which occupied all but about 1GB of the disk) and a swap partition. I had mounted it successfully and was browsing files, before I ...
1
vote
1answer
78 views

How much space does an inode occupy?

In Windows, when a file/folder is created, it is associated with an FRN (a unique number which is like an Index into the MFT). All the file metadata is stored in the MFT which occupies a reserved size ...
12
votes
3answers
626 views

Can the filesystem become inconsistent if interrupted when moving a file?

I have two folders on the same partition (EXT2) If I mv folder1/file folder2 and some interruption occur (e.g. power failure) could the file system ever end up being inconsistent? Isn't the mv ...
2
votes
1answer
41 views

Backup partition changed UUID without user interaction

I recently had to purchase a new hard drive. Since I was at it I bought two instead of one as they were on offer (both are the same model). Since there was a lot of space left on the second hard disk ...
7
votes
2answers
1k views

What is the difference between “inode size” and “Bytes per inode”

Below information is taken from man page,I would like to know the difference between bytes-per-inode and Inode-size? -i bytes-per-inode Specify the bytes/inode ratio. mke2fs creates an inode for ...
2
votes
1answer
287 views

How to extract raw ext3 inode data from disk?

On an ext3 (or ext2/4, pick your flavor) filesystem, how would one extract raw byte data that corresponds to a particular inode directly from the hard drive? Is it possible given, say, an inode number ...
1
vote
1answer
164 views

Creating disk device in a file

I'm trying to create disk device in a file with: dd if=/dev/zero of=file.img bs=516096 count=1000 sudo losetup /dev/loop0 file.img (echo n; echo p; echo 1; echo ""; echo ""; echo w;) | sudo fdisk -u ...
0
votes
1answer
2k views

Ext2 filesystem for /boot partition

Is the ext2 filesystem good for /boot partition? I set ext4 for / root partition, but wasn't sure which filesystem to select for the /boot partition, and I just set ext2. Does it matter in this case?
1
vote
1answer
157 views

How are large directories stored (one inode or many?)

I've been studying up on the ext2 file system and inodes, and I'm not quite understanding a few things. How big is an inode? The output from tune2fs says its 256 for my system, so is that 256 byes? ...
4
votes
1answer
497 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 ...
0
votes
1answer
88 views

Is there any alternative to genext2fs in RHEL?

I am tryting to make initrd file system following [this tutorial][1] My host system is RHEL 6 64 bit. I am unable to get the required command: genext2fs No rpm is available for it, neither ...
6
votes
2answers
2k 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 ...
4
votes
2answers
584 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 ...
2
votes
1answer
821 views

Ext2 block structure: size of reserved GDT Blocks

In every publication I found about ext2, the structure of a block group is defined as following: Super Block: 1 block Group Descriptor: N blocks Data Bitmap: 1 block Inode Bitmap: 1 block Inode ...
0
votes
1answer
222 views

libext2fs gcc linking error

I am writing a C program which uses libext2fs: #include <ext2fs/ext2fs.h> int main(int argc, char *argv[]) { char *fsname = argv[1]; errcode_t err; ext2_filsys fs; err= ...
5
votes
1answer
580 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 ...
4
votes
1answer
1k 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
1answer
169 views

Relation between “Block Size”and “Upper Limits” in ext2

A similar looking question asks for the reason why the upper file limit could be 2 TB in ext2. I am trying to understand but the Documentation on ext2 but find this hard. Please correct me if I'm ...
2
votes
1answer
201 views

Minimizing “idle” writes on a file system

Leaving out many details, I need to create a read/write file system on a device with the following main goals: Eliminate all writes while data is not being explicitly written. Reduce all indirect ...
5
votes
1answer
2k views

What determines the maximum file size in ext2 file system

I was reading the Kernel Documentation where it says There are various limits imposed by the on-disk layout of ext2. Other limits are imposed by the current implementation of the kernel code. ...
3
votes
1answer
50 views

Having error during Ubuntu installation

I have Ubuntu on a USB stick. When I boot from it (select boot from this USB), it shows some logs like usual. I also see the Ubuntu logo with 5 dots below, but then I get these: ext2_lookup deleted ...
1
vote
1answer
778 views

Ext4 exhibits unexpected write latency variance vs. ext2

I have a latency sensitive application running on an embedded system, and I'm seeing some discrepancy between writing to a ext4 partition and an ext2 partition on the same physical device. ...
1
vote
1answer
301 views

Cannot make anyfs-tools. My e2fslibs package seems not to be the compatible version

anyfs-tools promises to convert a ntfs partition into ext3. That's what I want to do. (I have backed up what was necessary). But when I try to compile anyfs-tools I get a make compilation error ...
47
votes
7answers
43k 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?
3
votes
2answers
1k views

Besides the journal, what are the differences between ext2 and ext3?

I just saw an answer question about filesystems for embedded hardware on another Stack Exchange site. The question was "What file system format should I use on flash memory?" and the answer suggested ...
9
votes
2answers
8k 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 ...
2
votes
1answer
2k views

Ext4 support in Grub 0.9X (legacy) and Grub 1.9X (Grub2)

I'm about to setup my new USB key with Grub or Grub2. In the old days I used ext2 for the boot partition. I'm wondering if I could use ext4 for Grub2? And if use Grub 0.9X, what about support of ...
7
votes
3answers
2k 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?
2
votes
1answer
11k 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
2answers
4k views

Salvage files from ext3 filesystem with physical errors

I have a disk from a crashed Linux laptop with files on it that the unhappy owner would like to have back if at all possible (no backup solutions please). I have not had anything to do with it ...
7
votes
1answer
945 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 ...
1
vote
2answers
104 views

Is the sticky bit not used in current file systems

Can I safely conclude that the sticky bit is not used in current file sysems and reuse the bit for my own purpose.
5
votes
3answers
311 views

Is ext2 suitable for daily use on a desktop or laptop?

Is a journaling filesystem needed in today's desktop world? A good OS doesn't kernel panic every month, and if we are using a laptop, then there aren't any power outages, so why shouldn't we use ...
5
votes
1answer
2k views

how much space to reserve on ext3 filesystem to prevent fragmentation issues?

I wondered about some missing space on my ext3 partition and, after some googling, found that debian based ubuntu reserves 5% of the size for root. I also found posts describing how to change that ...
4
votes
3answers
2k views

How many bits is the access flags of a file?

How many bits on a linux file system is taken up for the permissions of a file?
6
votes
2answers
406 views

Defragging an ext partition?

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

Remove a corrupted file in a Linux system

How to remove a file that is corrupted? In Linux (Fedora based), when I type: ls -l I get drwxr-xr-x. 2 dmiller3 dmiller3 4096 Jul 26 13:57 SomeFile ?????????? ? ? ? 4096 ...