What does the "dd"ing for an SSD do?


#1

by young » Sun Nov 04, 2012 9:27 pm

What does the "dd"ing of an SSD do?

Aerospike recommends that prior to using an SSD for the first time, that you clear the SSD. Use the following command (you will need roo/sudo privileges)

sudo dd if=/dev/zero of=/dev/sdx bs=128k &/

Here “sdx” is the device of the SSD in question.

This will zero out the drive and make sure that any data there has been cleared out.

You can run these commands in parallel for multiple SSDs.


#2

Sometime error messages are printed when doing the dd command, e.g., “No space left on device” and in case of Amazon, we get “out of space error”. How can one know that the dd worked successfully?


#3

The message regarding “No space left” or “Out of space error” when doing dd itself is an indication that dd has reached the end of disk. This usually is a mark of success.

To monitor dd, you can use:

bash$ while [ 1 ]
do
kill -USR1 [pid_of_dd]
sleep 60
done