SMART Power Off Retract Count and Load Cycle Count

[BlueDragon]

Hi,
I just received my new (?) HDD in an open antistatic bag with following SMART attributes:

Code: Select all

ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x002f   100   253   051    Pre-fail  Always       -       0
  3 Spin_Up_Time            0x0027   100   253   021    Pre-fail  Always       -       0
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       3
  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   100   100   000    Old_age   Always       -       0
 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       -       3
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       1
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       1
194 Temperature_Celsius     0x0022   117   117   000    Old_age   Always       -       30
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   100   253   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x0008   100   253   000    Old_age   Offline      -       0

I'm a bit puzzled about the interpretation of these values... I understand the spindle has started to rotate 3 times (SMART attribute #4) which is in line with the power cycle count of 3 (SMART attribute #12). Now what about this 'Power Off Retract Count' (SMART attribute #192) and the 'Load Cycle Count' (SMART attribute # 193) of both being only 1?

Goggling around I found many quite contradictory explanations about these 2 latter attributes:
#192:
Wikipedia: "Count of times the heads are loaded off the media. Heads can be unloaded without actually powering off."
HD Sentinel: "Count of power off cycles"
Both these information are logically not fitting together. And in this SMART example above clearly the the drive has been powered up/down 3 times but power off retract count is only 1. How can that be?
#193:
Wikipedia: "Count of load/unload cycles into head landing zone position."
HD Sentinel: "Count of load/unload cycles"
How can the drive in this example above has been power cycled 3 times and the head unloaded only 1 time??

In any case this HDD is not totally new, since it has been power cycled at least 2 times before I connected it. Not a big problem at all I guess but still a bit unpleasant, given the fact that the manufacturing date is Jan 2014 and I just received it today. Like I'm used to do I will start a surface scan before I will fill it with data.

BTW what would you guys advise to check / test basically before starting to use a new (?) drive? Simple surface read scan or filling it with zeros or more?

Thanks for your answers!

[hdsentinel]

Thanks for the details.
First of all, I must tell that the list of attributes is not complete (not from Hard Disk Sentinel), so I'm not sure if all values reported correctly.
Also without knowing the actual hard disk manufacturer, model and firmware version (yes, it may be also important to properly identify the S.M.A.R.T. values and understand how they work with a particular drive) it is hard to say anything for 100% sure.

Generally, Hard Disk Sentinel is designed exactly to do this - so it is not required to manually check the attributes one-by-one. You can do it of course (and even verify how they change with time) but Hard Disk Sentinel is designed to report any kind of problem(s).

To diagnose the hard disks, please check: http://www.hdsentinel.com/faq.php#tests
( Hard disk health is low or recently changed or I just installed a new (used) hard disk. How can I perform a deep analysis? )
which exactly describes what you should do to verify if the hard disk (even a new one) is perfect - or to reveal and fix any kind of problems before using for actual storage of important, sensitive data.


> I understand the spindle has started to rotate 3 times (SMART attribute #4)

Yes.

> which is in line with the power cycle count of 3 (SMART attribute #12)

Yes.

> Now what about this 'Power Off Retract Count' (SMART attribute #192) and the

The 192 Power Off Retract Count attribute usually increases on non-standard power OFF cycles, for example caused by sudden power failure, power loss or hard reset. This is usually lower than the start/stop count, ideally 0.

It is important to know that when the drives arrive from the factory, some counters (for example the ones you mentioned) may be not zero.
Usually the power on time counter (attribute 9) is zero, but some others usually not.
This is completely normal.

As long as these counters are fairly low and the power on time value is also zero (or 1), you can be sure that the drive is new.

[BlueDragon]

Thank you very much for your reply and advises.

Actually it's the SMART status of a WD Red 2TB HDD.

Some drives like you said may have non zero values already when just opened from the sealed anti-static bag. I did not verify this by myself since in the past I was not going so deep in SMART queries and stuff like that, like I do now. All I can say is that just a few days ago I buyed a new Intel SSD Series 530 and it arrived in a sealed box and bag. I started it and immediately had a look at the SMART attributes (with smartctl) and even the time counter (precise on the second, though rounded up to the min by hdsentinel) was starting with zero. So maybe there are different ways of doing from the manufacturer but I would expect a new drive to have zero values everywhere, especially power cycle and power on time. As regard to the WD Red drive the reseller admitted that it had been taken from a NAS and later on I even discovered the linux swap and ext4 partitions on it. So it was definitely not new and he actually cheated me. For this reason I sent him already the drive back.

Thanks again for your good work and this nice tool!

[hdsentinel]

Thanks, I see!
Yes, if the drive had partition(s), then this is an other question, then it was definitely used.

Jut a tip: in Hard Disk Sentinel you can use Disk -> Surface Test option and (without starting the test) click on View.
Then just click on the disk surface map to view the "raw" contents of any sector. These should be all empty (zeroes), so if you inspect some sectors (for example sector 0) you can quickly check if the drive was empty - or if it previously had any kind of data.

[BlueDragon]

Yes good idea to also look at the sector level.

Thanks again!

[BlueDragon]

Hi,

I just wanted to confirm what you stated above. On some new disks (in this case a WD green 2TB, factory sealed) the SMART attributes may be other then zero. I just had a case with a start / stop count of 2, power cycle of 2, power retract of 1 and LLC of 6. So obviously some brands are already starting the disks for a final check I assume.

[hdsentinel]

Yes, exactly as you wrote: some counters may be non-zero even on a new hard disk. This is normal.
The Start/stop count, power cycle count, load/unload cycle count can have some initial values (1, 2 or so).

The LLC = 6 seems a bit high for me for a completely new hard disk and also the power retract is usually zero according the experiences but the values you mentioned are still acceptable, depending on the drive.

Personally I'd say the most important is the "power on hours". If that one is zero and the others show only minimal change, then there are no troubles.

Regardless of the age, I'd start with complete testing first before using the drive to store actual data (as described at http://www.hdsentinel.com/faq.php#tests )

[BlueDragon]

The LLC = 6 seems a bit high for me for a completely new hard disk and also the power retract is usually zero according the experiences but the values you mentioned are still acceptable, depending on the drive.

Since it's a WD green drive they are notorious for having this (crazy) setting of 8 seconds before to park (unload). So actually doing simple maths after only a minute powered on it could already reach this figure, if for any reason they would be accessed only every 10 seconds. With these green drives I reach LLC values of around 380'000 !! after 3 years of power on (more or less 24/7) and for these element external USB cases WD is not even proposing any software to change these settings...

[hdsentinel]

Hard Disk Sentinel can help in this field:

open Configuration -> Disk Control page and in the "Do not allow spin down of hard disks" field enter a
*
(star) character. Then Hard Disk Sentinel (while active) prevents unloading by periodically sending a command to the hard disk. This prevents sleep / spin down / parking (this would also keep load-unload count low and maintain better performance).

This can be used with any hard disks, not only WD Greens.

BTW, WD has a tool called WDIDLE for this purpose, but according the experiences, it does not work in all situations, depends on motherboard / chipset / controller etc.

[BlueDragon]

Thanks for this other nice hint!

Actually what I don't understand with these external USB Elements HDD is that they seem never to spin down (sleep), even when not accessed for a longer time (I suppose but hard to know exactly what the various apps are doing in the background). Then strangely they unload and load almost all the time (given these astronomical LLC values)...

BTW, WD has a tool called WDIDLE for this purpose, but according the experiences, it does not work in all situations, depends on motherboard / chipset / controller etc.

Yes I know, I have been reading and searching very extensively about this topic. But the problem is that this WDIDLE3 utility is NOT working over USB (or at least I could not have it work and I did not find someone reporting that it could be done, besides the story of booting in DOS with USB support or even in linux, I did not manage to have it work so far!). In any case it's a shame from WD...