User manual

Hitachi hard disk drive specifications
64
9.6.4.4 User Password Lost
If the User Password is forgotten and High level security is set, the system user can't access any data. However,
the device can be unlocked using the Master Password.
If a system user forgets the User Password and Maximum security level is set, data access is impossible.
However, the device can be unlocked using the Security Erase Unit command to unlock the device and erase all
user data with the Master Password.
User Password Lost
LEVEL ?
High
Unlock CMD with Master Password
Maximum
Normal operation
Erase Prepare Command
Erase Unit Command
with Master Password
Normal operation but data lost
Figure 12 Password Lost
9.6.4.5 Attempt limit for SECURITY UNLOCK command
The SECURITY UNLOCK command has an attempt limit. The purpose of this attempt limit is to prevent that
someone attempts to unlock the drive by using various passwords many times.
The device counts the password mismatch. If the password does not match, the device counts it up without
distinguishing the Master password and the User password. If the count reaches 5, EXPIRE bit (bit 4) of Word
128 in Identify Device information is set, and then SECURITY ERASE UNIT command and SECURITY
UNLOCK command are aborted until a hard reset or a power off. The count and EXPIRE bit are cleared after a
power on reset or a hard reset.