Data Dump Progress

adri_ht_ · 04-26-2009, 10:13 PM

Hey guys,

Lately I have been doing partition and disk cloning with dd, but I hate not to have a progress bar. I have googled a lot, but I can't find a straight answer to the matter. I know that by calling the pid or something I would get a dump of the progress.

Any hint will be greatly appreciated.

Thanks

Tinkster · 04-27-2009, 01:55 AM

from "man dd"

Code:

       Sending a USR1 signal to a running `dd' process makes it print I/O sta-
       tistics to standard error and then resume copying.

              $ dd if=/dev/zero of=/dev/null& pid=$!
              $ kill -USR1 $pid; sleep 1; kill $pid

It's amazing how much information those manuals provide ...

Cheers,
Tink (your personal man page search engine)

adri_ht_ · 04-27-2009, 10:36 AM

Quote:

Originally Posted by Tinkster

from "man dd"

Code:

       Sending a USR1 signal to a running `dd' process makes it print I/O sta-
       tistics to standard error and then resume copying.

              $ dd if=/dev/zero of=/dev/null& pid=$!
              $ kill -USR1 $pid; sleep 1; kill $pid

Thanks for your prompt reply, and yes I always forget that man pages have most of the answers. Now, the above procedure is kind of confusing.

How would I apply that concept to this for example:

Code:

dd if=/dev/hda1 of=/dev/sda1 bs=4096

What is the meaning of the & and ! symbols. I know $ is used for variables.

On the net, I found similar way of doing it. A lot easier I think. Just by finding the pid of dd:

ps -A | grep dd

I can use the kill -USR1 to dump the progress:

kill -USR1 pid

Nevertheless, I would like to understand the way the man pages does it.

Tinkster · 04-27-2009, 03:20 PM

Well ... pid=$! stores the PID of the previous command (dd) in the
variable pid. It saves you having to try and find it using ps & grep
(two commands you needn't run using the method mentioned in the manual).

The ampersand put the dd into the background (so you can get the terminal
back and actually execute pid=$! [w/o having to do Ctrl-z and bg]).

man bash for details on $!, & and the likes ;}

Cheers,
Tink

chrism01 · 04-27-2009, 08:43 PM

Here's some good guides to Linux and bash:

http://rute.2038bug.com/index.html.gz
http://tldp.org/LDP/Bash-Beginners-G...tml/index.html
http://www.tldp.org/LDP/abs/html/