On 10/21/10 15:20, Dag-Erling Smørgrav wrote:
Bruce Cran<[email protected]>  writes:
The Ubuntu issue was what I was thinking of - I got that mixed up with
the aggressive power management of the WD EARS drives.
The entire Green series, actually, which includes models such as the
EADS, AARS etc., but there's more to them than that - the central
feature is their dynamically adjusted rotational speed, which allows
them to conserve power without spinning all the way down.

DES

Actually, the green series does spin all the way down, well at least the drive I have does. Here is the output from one of my drives, that I do not think has long left to live.

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital Caviar Green family
Device Model:     WDC WD5000AADS-00M2B0
Serial Number:    WD-WMAV51882791
Firmware Version: 01.00A01
User Capacity:    500,107,862,016 bytes
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   8
ATA Standard is:  Exact ATA specification draft version not indicated
Local Time is:    Thu Oct 21 23:31:35 2010 BST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
....
SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail Always - 0 3 Spin_Up_Time 0x0027 111 104 021 Pre-fail Always - 7425 4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 98 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0 7 Seek_Error_Rate 0x002e 100 253 000 Old_age Always - 0 9 Power_On_Hours 0x0032 093 093 000 Old_age Always - 5295 10 Spin_Retry_Count 0x0032 100 253 000 Old_age Always - 0 11 Calibration_Retry_Count 0x0032 100 253 000 Old_age Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 96 192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always - 95 193 Load_Cycle_Count 0x0032 001 001 000 Old_age Always - 781014 194 Temperature_Celsius 0x0022 120 102 000 Old_age Always - 27 196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0030 200 200 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0008 200 200 000 Old_age Offline - 0


The datasheet for these drive <http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-701229.pdf>http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-701229.pdf says
"Reliability/Data Integrity
Load/unload cycles (3)         300,000
Limited Warranty (years) (4)
(3) Controlled unload at ambient condition
(4) The term of the limited warranty my vary by region"

Also http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/std_adp.php?p_faqid=5357
"(drive has been validated to 1 million load/unload cycles without issue)"

Im already at 781014 load cycles, yet the drive is only about 7 months old. Doing the math, I am getting a load/unload cycle about every 24.5 seconds Another 2 months and I will be knocking on for 1 million load/unload cycles....

As DES has already said, for most people the extra load/unload cycles when rebooting a computer will not be an issue at all and is far more desirable than an emergency park when powering down


Paul
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