How do I determine the block size of an ext3 partition on Linux?

Question

score 75 · Accepted Answer · answered Jun 22 '09 at 18:07

75

# tune2fs -l /dev/sda1 | grep -i 'block size'
Block size:               1024

Replace /dev/sda1 with the partition you want to check.

answered Jun 22 '09 at 18:07

skraggy

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mik · Answer 2 · 2019-09-26T09:40:40.977

49

Without root, without writing, and for any filesystem type, you can do:

stat -fc %s .

This will give block size of the filesystem mounted in current directory (or any other directory specified instead of the dot).

edited Sep 26 '19 at 09:40

answered Oct 12 '15 at 15:13

mik

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Don't forget the dot at the end of that command as `stat -f` is expecting is expecting a folder to give you stats about. – BeowulfNode42 Jan 09 '17 at 00:11
And to further narrow it down to what the OP asked for: `stat --printf='%s' -f .` – Jani Uusitalo May 19 '17 at 15:01
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with newlinestat --printf='%s\n' -f . – c4f4t0r Mar 28 '18 at 09:48
1

@JaniUusitalo, @c4f4t0r: thanks for the hint, corrected the answer using `-c` which is simpler than `--printf='...\n'` – mik Mar 28 '18 at 14:14

score 13 · Answer 3 · edited Oct 15 '12 at 09:59

13

dumpe2fs -h /dev/md2

will output something with:

Block size:               4096
Fragment size:            4096

edited Oct 15 '12 at 09:59

quanta

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answered Feb 20 '11 at 15:00

evcz

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score 10 · Answer 4 · answered Dec 11 '14 at 09:31

10

In the case where you don't have the right to run tune2fs on a device (e.g. in a corporate environment) you can try writing a single byte to a file on the partition in question and check the disk usage:

echo 1 > test
du -h test

answered Dec 11 '14 at 09:31

narthi

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score 7 · Answer 5 · answered Jun 22 '09 at 18:50

7

On x86, a filesystem block is just about always 4KiB - the default size - and never larger than the size of a memory page (which is 4KiB).

answered Jun 22 '09 at 18:50

wzzrd

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1

This is the same on every platform, the largest block size is supported by ext2/3 is 4096 bytes. – Dave Cheney Jun 23 '09 at 10:06
Thanks Dave! I learned something today ;-) I originally thought the ext3 blocksize could be 8k on platforms that supported 8k memory pages. – wzzrd Jun 23 '09 at 12:44
Wikipedia says it can be 8k: http://en.wikipedia.org/wiki/Ext3#Size_limits – dfrankow Apr 25 '12 at 22:41
1

@dfrankow: if you have 8k memory pages, such as on Alpha hardware, yes. But you do not have those on x86 hardware and that is what I was talking about. – wzzrd Apr 26 '12 at 08:03

score 5 · Answer 6 · edited Jul 03 '19 at 11:43

5

To detect block size of required partition:

Detect partition name:
```
$ df -h
```
for example we have /dev/sda1
Detect block size for this partition:
```
$ sudo blockdev --getbsz /dev/sda1
```

edited Jul 03 '19 at 11:43

Pablo A

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answered Jun 13 '17 at 09:00

lospejos

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score 0 · Answer 7 · edited Jul 03 '19 at 08:49

0

Use

sudo dumpe2fs /dev/sda1 | grep "Block size"

where /dev/sda1 is the device partition. You can get it from lsblk

edited Jul 03 '19 at 08:49

Pablo A

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answered Aug 27 '09 at 00:43

score 0 · Answer 8 · edited Jul 29 '15 at 17:54

0

stat <<Filename>>

will also give file size in blocks

edited Jul 29 '15 at 17:54

Michael Hampton

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940

answered Jul 29 '15 at 15:54

Mayur

21

This is not what the OP asked – Pablo A Jul 03 '19 at 07:55

How do I determine the block size of an ext3 partition on Linux?

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