Is there a method of getting a percentage on a DD in linux?
See answers from this question 
For example you can use
pv before you start
sudo apt-get install pv # if you do not have it pv < /dev/sda > /dev/sc3 # it is reported to be faster pv /dev/sda > /dev/sc3 # it seems to have the same speed of the previous one #or sudo dd if=/dev/sda | pv -s 1844G | dd of=/dev/sdc3 # Maybe slower
440MB 0:00:38 [11.6MB/s] [======> ] 21% ETA 0:02:19
Especially for large files you may want to see
man dd and set the options needed to speed up all on your hardware, e.g.
bs=100M to set the buffer,
oflag=sync to count the effective bytes written, maybe
-s only takes integer parameters so
As you can notice from the first lines you do not need
dd at all.
kill -USR1 pid
If you already launched the
dd command, once you have individuated its PID (Ctrl-Z +
bg and you read it , or
pgrep ^dd ... ) you may send a signal
SIGINFO see below) and read the output.
If the PID of the program is 1234 with
kill -USR1 1234
dd will answer on the terminal of its STDERR with something similar to
4+1 records in 4+0 records out 41943040 bytes (42 MB) copied, 2.90588 s, 14.4 MB/s
Warning: Under OpenBSD you may have to check in advance the behaviour of
kill: use instead
kill -SIGINFO 1234.
It exists the sigaction named
SIGUSR1 one, in this case, should terminate the program (
Under Ubuntu use
My go-to tool for this kind of stuff is
This tool can be described as a Tiny, Dirty, Linux-and-OSX-Only C command that looks for coreutils basic commands (cp, mv, dd, tar, gzip/gunzip, cat, etc.) currently running on your system and displays the percentage of copied data. It can also show estimated time and throughput, and provides a "top-like" mode (monitoring).
It simply scans
/procfor interesting commands, and then looks at directories
fdinfoto find opened files and seek positions, and reports status for the largest file.
It's very light, and compatible with virtually any command.
I find it particularly useful because:
- compared to
pvin pipe or
dcfldd, I don't have to remember to run a different command when I start the operation, I can monitor stuff after the fact;
- compared to
kill -USR1, it works on virtually any command, I don't have to always double-check the manpage to make sure I'm not accidentally killing the copy; also, it's nice that, when invoked without parameters, it shows the progress for any common "data transfer" command currently running, so I don't even have to look up the PID;
- compared to
pv -d, again I don't need to look up the PID.
dd, then, in a separate shell, invoke the following command:
pv -d $(pidof dd) # root may be required
This will make pv obtain statistics on all the opened file descriptors of the
dd process. It will show you both where the read and write buffer sit.