4
votes
1answer
55 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 ...
6
votes
1answer
472 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
147 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 ...
1
vote
1answer
61 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?
0
votes
1answer
44 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
2answers
580 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 ...
4
votes
1answer
194 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
326 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 ...
3
votes
3answers
224 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 ...
5
votes
1answer
840 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 ...
32
votes
6answers
16k 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
1answer
197 views

How do I choose between ext 3 and 4?

I tried looking at the difference, the main ones seem to be 4 supports more subdirectories in a file, supports larger files, has delayed write which I don't prefer as I don't want data loss. I also ...
2
votes
1answer
304 views

How to fix a fragmented ext disk - myth or truth?

I just read this article about the virtually non-existent disk fragmentation on *nix filesystems. It was mentioned that due to the way ext handles writing data to the disks, fragmentation may only ...
8
votes
2answers
4k 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 ...
6
votes
3answers
1k 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?
1
vote
3answers
600 views

is it safe to backup ext4 partition with partimage , which is detected as a ext3 partition

I use partimage to backup my ext4 partition, but during backup, the partition was detected as an ext3 partition. So I'm wondering if this can cause something bad.
6
votes
1answer
694 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 ...
11
votes
7answers
45k 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 ...
6
votes
1answer
1k 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) ...
3
votes
2answers
314 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
2answers
965 views

Recover formatted ext3 partition

Suppose you have an ext3 partition which was unfortunately formated as ext4 partition (and where now are some but not a lot new files on it). Is there any way to recover (some) files from the old ext3 ...