Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
305
20.1.9
Degraded Mode
There are certain errors or conditions which may impair the ability of the drive to function normally. Rather than fail
hard the drive is designed to be as responsive as possible. Also, in most cases, some action on the part of the
initiator may be used to restore normal operation. This mode of limited operation is called Degraded Mode.
There are 3 conditions in the Degraded Mode:
- Spindle Motor Degrade which is caused by one of the following conditions:
- Spindle Motor was started (by POR or Unit Start command) and the Target is under Self Configuration.
- Spindle Motor Failed to start.
- Spindle Motor was stopped by Unit Stop command after the Target successfully completed the Self
Configuration.
- Self Configuration Failure Degraded which is caused by one of the following conditions:
- RAM Code, Configuration Sector Read Failure
- RAM Code, Configuration Sector Revision Mismatch
- Format Command Failure Degraded. This condition is caused when Format Unit command failed or was
interrupted abnormally (Mode Page 0, byte 5, bit 4 FDD controls Format Degraded mode)
20.1.9.1
Response to SCSI Command in Degraded Mode - Disable
Auto Start
The tables on the following pages show the degraded mode status with acceptable commands and additional sense
codes
Table 274 Spindle Motor Degraded Mode - Disable Auto Start
Command (w/Option)
Response
Request Sense
Executed. The Target may return Sense Key 02h (Not Ready) ASC/ASCQ 0402h
(Initialize Command Required)
Inquiry (EVPD=0)
Executed
Inquiry (EVPD=1)
Executed and Check Condition is returned with Sense Key 05h (Illegal Request)
ASC/ASCQ 2400h (Invalid Field in CDB)
Test Unit Ready
Executed and Check Condition is returned with Sense Key 02h (Not Ready) ASC/ASCQ
0402h (Initialize Command Required)
Start Stop Unit
(Start)
Executed
- Success: Good Status is returned. Motor Degraded Mode is cleared
- Spindle Motor Start Failure: Check Condition with Sense Key 02h (Not Ready)
ASC/ASCQ 0400h (Start Spindle Motor Fail)
-
Self Configuration Failure: Check Condition with Sense Key 02h (Not Ready)
ASC/ASCQ 4080h (Diag Fail- Bring up Fail)
Sense Key 02h (Not Ready) ASC/ASCQ 4085h (Diag Fail-RAM Code NOT load)
Start Stop Unit
(Stop)
Executed. Good Status is returned. Motor Degraded Mode is NOT cleared
Other Commands
Not Executed. Check Condition Status is returned with Sense Key 02h (Not Ready)
ASC/ASCQ 0402h (Initialize Command Required)