Normal data deletion does not erase all data from SSD as same parts are reserved and omitted by removal process. The function secure erase function allows for a complete data removal from all cells. The secure erase function is offered by SSD manufactures and not all hard drives or Linux kernels support it. In the below examples we will refer to /dev/sda block device as our test drive. To find whether your SSD hard drive supports secure erase run a following linux command:
Warning:
ATA Security Feature Set
These switches are DANGEROUS to experiment with, and might not work with some kernels. USE AT YOUR OWN RISK.
# hdparm -I /dev/sda | grep erase supported: enhanced erase
The drive should also list master password for secure erase:
# hdparm -I /dev/sda | grep pass Master password revision code = 65534
You can all attempt to set your own password:
# hdparm --user-master u --security-set-pass 111111 /dev/sda
To start secure erase data removal you can do:
# hdparm --user-master u --security-erase 111111 /dev/sda