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Olnex

Member

Registered: 2008-04-10

Posts: 89

Is Spin-up/Spin-down "Load_Cycle_Count" or "Start_Stop_Count"?

My HDD suffered from the spin-up/spin-down too often problem, this used to be a famous problem in Ubuntu, I was searching on the web and found:

"
Some of that report is the result of a misunderstanding:
my Load_Cycle_Count is now at 718,694. this is very bad because the average Load_Cycle_count before failure for most hard disks is 600,000.
This is simply not true. Most laptop drives have a specification that says that it should survive approximately half a million spin-up/spin-down. But Load_Cycle_Count is not spin-up/spin-down (which is tracked by Start_Stop_Count instead). Most drives specs don't say anything about the expected number of "load_cycle" that the drive is expected to survive. This high number of load_cycle is because the drive aggressively moves (unloads) the head away from the disk after a very short time of idleness. It does this not so much to save power as to avoid crashing the head against the disk in case of a shock. I.e. this number is high so as to avoid data loss.

Other drives only unload the heads when the disk spins up/down, so on some drives Start_Stop_Count=Load_Cycle_Count. Yet others don't even bother to report Load_Cycle_Count.
"

from:
http://lists.debian.org/debian-laptop/2 … 00073.html

So I am confused, is the number which increases too fast represented as "Start_Stop_Count" or "Load_Cycle_Count" that has a 600000 limit? For my HDD, the values of the two attributes are not equal so they do not mean the same thing, and should "Start_Stop_Count" actually be the times that HDD got powered on and off?

Anyone has Load_Cycle_Count increasing too fast? Or even over 600000 and HDD is still healthy?

Thanks!

graysky

Wiki Maintainer

From: :wq

Registered: 2008-12-01

Posts: 10,597

Website

Re: Is Spin-up/Spin-down "Load_Cycle_Count" or "Start_Stop_Count"?

Dunno.. see: https://wiki.archlinux.org/index.php/Ad … Green_HDDs

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eduardo.eae

Member

From: Reconquista - Argentina

Registered: 2010-01-24

Posts: 68

Re: Is Spin-up/Spin-down "Load_Cycle_Count" or "Start_Stop_Count"?

Start_Stop_Count 7381
Load_Cycle_Count 140775
11 months old laptop

I noticed that Load_Cycle_Count was high and after a little browsing I found that with hdparm -B 200 it increse very slow now.

Nonetheless I would like to be able to use hdparm -B 1 to save more power and protect the disk from shock. But if it shorten the life of my disk I find it unviable to me.

TigTex

Member

From: Portugal

Registered: 2008-06-19

Posts: 301

Re: Is Spin-up/Spin-down "Load_Cycle_Count" or "Start_Stop_Count"?

That "load_cycle_count" is 600'000 for laptop hdd's yes. Some rare combinations of hardware cause the system to unload hdd's heads very often and makes that value reach it's limit very fast. The solution is using hdparm or using it's proprietary "DOS" utilities to change the APM value directly on it's firmware.

Start_Stop_Count=Load_Cycle_Count -> this is true for desktop hdd's that don't park his heads for safety (since it's not a laptop, doesn't need to do that).

Start_Stop_Count, Load_Cycle_Count are the most important values that tell you the health of your hard disk drive (lower = better).

If your load_cycle_count is above it's limit, backup all your data as soon as possible. If you see that load_cycle_count is increasing too fast (200+ unloads per hour), use some software (that I said above) to avoid that and/or search for firmware updates and bios updates.

Last edited by TigTex (2010-11-27 18:42:10)

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eduardo.eae

Member

From: Reconquista - Argentina

Registered: 2010-01-24

Posts: 68

Re: Is Spin-up/Spin-down "Load_Cycle_Count" or "Start_Stop_Count"?

I read that the reason that the disk's head unload so often is a manufacturer problem.
The disks are designed mostly for windows. Windows almost never stop using the disk. Linux is better saving power in disks and can spend a longer time without using it so the head is unloaded more often.

ChoK

Member

From: France

Registered: 2008-10-01

Posts: 346

Re: Is Spin-up/Spin-down "Load_Cycle_Count" or "Start_Stop_Count"?

Some of that report is the result of a misunderstanding:
my Load_Cycle_Count is now at 718,694. this is very bad because the average Load_Cycle_count before failure for most hard disks is 600,000.

In structural engineering and materials, a batch of samples are usually tested so that 95% of them can sustain an arbitrary number of load cycles (billion cycles for a bearing for example), but even if they are rated only 600000 cycles, it just means that statistically no more than 5% of them will fail before. Some may fail at 1 million, some at 2 millions and even more.

I suppose HDD manufacturers are using something similar because it's the easiest way to test.

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Olnex

Member

Registered: 2008-04-10

Posts: 89

Re: Is Spin-up/Spin-down "Load_Cycle_Count" or "Start_Stop_Count"?

Thanks for your reply, I have a Hitachi HDD and there is a Feature Tool(bootable image) from Hitachi which can set the APM level into firmware, however, I'm using a Macbook dual-boot, there is no way to boot from the Feature Tool CD and I do not have a spare PC laptop with me, so I better go for the software hdparm way.

Thanks!