用WD網站抓的Data Lifeguard Diagnostic for DOS（CD）
來檢測硬碟，檢測完後結果是沒問題，

但是在FreeBSD下用smartmontools查看卻發現多出這樣紀錄

SMART Error Log Version: 1
ATA Error Count: 4
CR = Command Register [HEX]
FR = Features Register [HEX]
SC = Sector Count Register [HEX]
SN = Sector Number Register [HEX]
CL = Cylinder Low Register [HEX]
CH = Cylinder High Register [HEX]
DH = Device/Head Register [HEX]
DC = Device Command Register [HEX]
ER = Error register [HEX]
ST = Status register [HEX]
Powered_Up_Time is measured from power on, and printed as
DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes,
SS=sec, and sss=millisec. It "wraps" after 49.710 days.


Error 4 occurred at disk power-on lifetime: 3115 hours (129 days + 19 hours)
When the command that caused the error occurred, the device was active or idle.

After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
04 51 01 30 4f c2 e0 Error: ABRT

Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
b0 d6 01 be 4f c2 e0 00 00:03:47.061 SMART WRITE LOG
b0 da 01 00 4f c2 e0 00 00:03:46.986 SMART RETURN STATUS
80 44 00 00 44 57 e0 00 00:03:46.986 [VENDOR SPECIFIC]
b0 d6 01 be 4f c2 e0 00 00:03:46.962 SMART WRITE LOG
80 45 00 00 44 57 e0 00 00:03:46.962 [VENDOR SPECIFIC]

Error 3 occurred at disk power-on lifetime: 3115 hours (129 days + 19 hours)
When the command that caused the error occurred, the device was active or idle.

After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
04 51 01 30 4f c2 a0 Error: ABRT

Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
b0 d6 01 be 4f c2 a0 00 00:00:54.428 SMART WRITE LOG
b0 da 01 00 4f c2 a0 00 00:00:54.353 SMART RETURN STATUS
80 44 00 00 44 57 a0 00 00:00:54.353 [VENDOR SPECIFIC]
b0 d6 01 be 4f c2 a0 00 00:00:54.334 SMART WRITE LOG
80 45 00 01 44 57 a0 00 00:00:54.334 [VENDOR SPECIFIC]




SMART Self-test log structure revision number 1
Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error
# 1 Short offline Completed without error 00% 3151 -
# 2 Conveyance offline Completed without error 00% 3115 -

上面#1是用Hitach DFT檢測的，#2是用Data Lifeguard Diagnostic for DOS（CD)檢測的，
看結果都是沒問題，但是WD檢測程式跑完就會出現那些紀錄，DFT則不會，
這是怎麼回是呢？