[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
bug#9191: dd does not use the given block size > 2GB
From: |
Ole Tange |
Subject: |
bug#9191: dd does not use the given block size > 2GB |
Date: |
Thu, 28 Jul 2011 17:11:11 +0200 |
Hi Coreutils.
$ ./dd if=/dev/zero of=/dev/null bs=2G
gives the following in 'top':
23182 tange 20 0 2058m 2.0g 616 R 100 25.8 0:25.13 dd
So it actively uses 2 G. This is exactly what I would expect.
However, if I use 10G it mallocs 10 G but only uses 2 G:
$ ./dd if=/dev/zero of=/dev/null bs=10G
Apparently all I need to do is:
./dd iflag=fullblock if=/dev/zero of=/dev/null bs=10G
But for a normal user (indeed for me before I read the source) this
comes as a surprise.
I would like to suggest that if bs is bigger than the used block, then
you get a warning like this:
dd: given bs=10G but used bs=2G. To force using 10G use 'iflag=fullblock'
Also the man page should refer to 'iflag=fullblock' under 'bs' and 'ibs'.
$ ./dd --version
dd (coreutils) 8.12
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Written by Paul Rubin, David MacKenzie, and Stuart Kemp.
/Ole
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- bug#9191: dd does not use the given block size > 2GB,
Ole Tange <=