# cat /proc/version 
Linux version 2.6.29.5-191.fc11.x86_64
 ([email protected])
 (gcc version 4.4.0 20090506 (Red Hat 4.4.0-4) (GCC) )
 #1 SMP Tue Jun 16 23:23:21 EDT 2009
# ./hdparm -V
hdparm v9.27
# lsscsi
[0:0:0:0]    cd/dvd  SONY     DVD-ROM DDU1615  FYS3  /dev/sr0 
[2:0:0:0]    disk    ATA      INTEL SSDSA2MH16 045C  /dev/sda 
[3:0:0:0]    disk    ATA      WDC WD1600BEKT-0 11.0  /dev/sdb 
[4:0:0:0]    disk    ATA      Maxtor 6Y120L0   YAR4  /dev/sdc 
# ./hdparm --security-set-pass NULL /dev/sda
security_password=""

/dev/sda:
 Issuing SECURITY_SET_PASS command, password="", user=master, mode=high
SECURITY_SET_PASS: Input/output error
# ./hdparm --security-erase NULL /dev/sda
security_password=""

/dev/sda:
 Issuing SECURITY_ERASE command, password="", user=master
ERASE_PREPARE: Input/output error