Can drives lose power-on hours?

[Rob Williams]

I decided to check my hard-drives SMART information a few days ago to make sure things were still going smooth after all this time, and found it odd that the Power_On_Hours value was way off. As you can see in the image, it's set to 1750 hours, or 73 days. This is a PC I've had on for almost 73 days at a time, so that figure is way off.

http://deathspawner.net/etcetera/pictures/forum_posts/etcetera/hard_drive_losing_power_on_hours.png

Are Power_On_Hours known to reset after 10,000 is hit? According to my calculations, I thought the drive would have around 12,000 hours, but if it's 10,000 + 1,750, then that would be damn close to that estimate. On the other hand, my three-year-old laptop harddrive (IDE) registers 15,437 hours... it didn't reset at all.

Anyone understand how this works better than I do?

[THUMPer]

It still works right? why worry? haha :)

[Rob Williams]

Considering I just saw two 750GB ES drives take a crap, I am overly skeptical now :-)

[Chaosratt]

I'm sorry to bump a slightly old post, but I just had a similar situation and I found this thread via a Google Search trying to find an answer.

Amazingly enough I had cacti running on the server in question and I have a perty graph to show you:
http://computingzone.org/gallery2/d/1897-1/poweron.png
Or link (http://computingzone.org/gallery2/v/misc/forums/poweron.png.html) if that doesn't work.

As you can see, the Power_on_hours was just under 1100 when it reset to 0 and began to increment again....

Does anyone have an explanation for this?

ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
3 Spin_Up_Time 0x0027 220 217 063 Pre-fail Always - 6890
4 Start_Stop_Count 0x0032 253 253 000 Old_age Always - 251
5 Reallocated_Sector_Ct 0x0033 253 253 063 Pre-fail Always - 0
6 Read_Channel_Margin 0x0001 253 253 100 Pre-fail Offline - 0
7 Seek_Error_Rate 0x000a 253 252 000 Old_age Always - 0
8 Seek_Time_Performance 0x0027 245 237 187 Pre-fail Always - 43215
9 Power_On_Minutes 0x0032 238 238 000 Old_age Always - 35h+14m
10 Spin_Retry_Count 0x002b 244 233 157 Pre-fail Always - 8
11 Calibration_Retry_Count 0x002b 253 252 223 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 253 253 000 Old_age Always - 226
192 Power-Off_Retract_Count 0x0032 253 253 000 Old_age Always - 0
193 Load_Cycle_Count 0x0032 253 253 000 Old_age Always - 0
194 Temperature_Celsius 0x0032 037 253 000 Old_age Always - 41
195 Hardware_ECC_Recovered 0x000a 253 252 000 Old_age Always - 23690


Edit:
Drive info if it might help:
=== START OF INFORMATION SECTION ===
Model Family: Maxtor DiamondMax 10 family (ATA/133 and SATA/150)
Device Model: Maxtor 6L100M0
Serial Number: ----------
Firmware Version: BANC1G10

[Rob Williams]

Hurrah for cacti, hah. Glad I am not the only one who saw this happen, especially with a completely different hard-drive. Is this a server you are running? Perhaps it's just Linux screwing with our drives. Although, my laptop has been running Linux for over two years and I don't see that problem there.

[Chaosratt]

Well, its the server hosting the page that image is on :P
AS for Linux itself doing it, I don't know. I've got my desktop with 3 drives in it, two pushing 5 and 8k, and a raptor pushing 18k without issue.

[Rob Williams]

The drive in question isn't on the server, though? As for Linux, I am not sure what the deal is. The drive in the laptop is just fine, so I am not entirely blaming Linux for anything, but it seems odd for a drive that should have thousands of hours accrued to only have under 2K.

It would be nice to know for sure, regardless. I am just glad the rest of my SMART health is fine, so I am confident nothing is actually wrong. Hopefully it's the same for yours.

[Chaosratt]

yes, the drive in question is in the server.
Its under very little load, spends most of its time idle. There is nothing running that might be interfacing with the drive in any unusual way that I am aware of. Just a simple php script running smartctl and piping the output into something the cacti poller can understand.