All Questions
19 questions
2votes
1answer
2kviews
File timestamps precision - ext3 with nanoseconds, ext4 with milliseconds
People say ext3 supports file timestamp precision up to seconds and ext4 up to nanoseconds. What happens is that my old VPS running Ubuntu 12.04 with an ext3 filesystem always (as far as I can ...
- 51
0votes
1answer
657views
Why is a filesystem type ext3/ext4 simultaneously?
My root directory looks like that: When I installed Ubuntu I create partition as ext4, but now it shows: Filesystem type:ext3/ext4. Another thing is that the pie chart shows three chart and ...
- 1,331
1vote
0answers
998views
How do I get ext3/ext4 filesystem features to apply in mke2fs?
As many of you know, ext3/ext4 have filesystem features that provide their special functionalities. Some of these features can be retrieved using dumpe2fs, for example, this output: Filesystem ...
- 56
8votes
3answers
5kviews
Optimize ext4 for always full operation
Our application writes data to disk as a huge ring buffer (30 to 150TB); writing new files while deleting old files. As such, by definition, the disk is always "near full". The writer process ...
- 643
1vote
0answers
130views
What happens to directory entry when a file is renamed [closed]
What exactly happens to the directory entry when a file is renamed? Is it that the entry of the oldfile is flushed and the newfile is replaced at it's place or a completely new entry is made at the ...
3votes
1answer
2kviews
ext3 vs ext4 - same disk size, less usable disk space under ext4 comparing to ext3. why?
Files copied from ext3 filesystem do not fit on same size ext4 filesystem. How to reproduce: create two 1GB files, setup loop device for each, create filesystem one ext3, one ext4, mount, rsync ...
- 31
8votes
4answers
7kviews
How do I create small disk image with large partitions
I am building a disk image for an embedded system (to be placed on an 4GB SD card). I want the system to have two partitions. A 'Root'(200Mb), and a 'Data' partition(800Mb). I create an empty 1GB ...
- 718
2votes
1answer
3kviews
Smallest file block size (ext 3, 4)
I'm curious, what is the smallest size a file can really be on Linux? (Assuming Ext3 fs, so why not ext4 fs as well). Sure you can write a file that only contains one byte, or maybe even less; but ...
- 4,612
3votes
1answer
301views
Many transient files on journaled filesystem?
Writing and deleting many files quickly I'm going to write many temporary files per second, over a sustained period. Each will be deleted after some milliseconds. Say we have an image processing ...
- 17.7k
7votes
2answers
6kviews
"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 fsck. ...
- 71
7votes
2answers
4kviews
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 (...
- 353
5votes
2answers
16kviews
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 ...
- 707
12votes
1answer
3kviews
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 ...
- 133
7votes
1answer
7kviews
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 ...
slm♦
- 378k
15votes
3answers
12kviews
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 ...
- 665
