How do I determine the block size of an ext3 partition on Linux?
Asked
Active
Viewed 1.1e+01k times
8 Answers
75
# tune2fs -l /dev/sda1 | grep -i 'block size'
Block size: 1024
Replace /dev/sda1 with the partition you want to check.
![](../../users/profiles/8193.webp)
skraggy
- 1,723
- 13
- 10
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).
![](../../users/profiles/316227.webp)
mik
- 591
- 5
- 6
-
3Don'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
-
1with 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
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
![](../../users/profiles/258080.webp)
narthi
- 201
- 2
- 2
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).
![](../../users/profiles/3950.webp)
wzzrd
- 10,269
- 2
- 32
- 47
-
1This 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
0
Use
sudo dumpe2fs /dev/sda1 | grep "Block size"
where /dev/sda1 is the device partition. You can get it from lsblk
![](../../users/profiles/407820.webp)
Pablo A
- 169
- 9