This guide describes how to wipe out the data on block storage or NAS attached to an instance. You can wipe out data by using scrub (Linux) or Disk Wipe (Windows) that can apply the DoD 5220.22-M pattern, which is the KISA data wiping standard.
Install the scrub package.
Debian or Ubuntu instance
$ sudo apt-get install scrub
$ sudo yum install scrub
Identify the storage device from which data will be wiped out.
$ df -h
Wipe out the data.
(For block storage) Apply the dod pattern
$ sudo scrub -p dod /dev/vdb1
(For NAS) Apply the dod pattern to the mounted directory
$ sudo scrub -p dod -X /home/ubuntu/nas/scrup
ERASE ALL and click the Finish button.