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Create a 5 MB blank file via a seek hole

Terminal - Create a 5 MB blank file via a seek hole
dd if=/dev/zero of=testfile.seek seek=5242879 bs=1 count=1
2011-04-04 17:56:47
Functions: dd
Create a 5 MB blank file via a seek hole

Similar to the original, but is much faster since it only needs to write the last byte as zero. A diff on testfile and testfile.seek will return that they are the same.


There is 1 alternative - vote for the best!

Terminal - Alternatives
dd if=/dev/zero of=testfile bs=1024 count=5000
2011-03-25 09:08:50
User: mpathi
Functions: dd

Useful for testing purposes

Know a better way?

If you can do better, submit your command here.

What others think

By replacing /dev/zero with /dev/null it won't even write that single byte -- quicker still!

Also, it makes the maths easier: you can abbreviate 5242880 to 5M (K = KiB, M = MiB, G = Gib, T = TiB)

dd if=/dev/null of=testfile.seek seek=5M bs=1 count=0
Comment by flatcap 212 weeks ago

How about using truncate instead of dd.

It is easier to use and faster than dd.

truncate -s 5M testfile


Comment by seungwon 211 weeks and 5 days ago

The file has the good size but not consume space on disque.

df -h /home

Filesystem Size Used Avail Use% Mounted on


1.9G 1.2G 607M 67% /home

dd if=/dev/zero of=testfile.seek seek=1G bs=1 count=1

1+0 records in

1+0 records out

1 byte (1 B) copied, 0.000159075 s, 6.3 kB/s

ll -h testfile.seek

-rw-r--r-- 1 itsys grpit 1.1G Apr 7 16:27 testfile.seek

df -h /home

Filesystem Size Used Avail Use% Mounted on


1.9G 1.2G 607M 67% /home

Comment by GouNiNi 211 weeks and 4 days ago

Your point of view

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