Current Pending Sector Count warnings on SSD


Gizmotoy

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Hello,

 

I've been receiving a ton of warnings about Current Pending Sector Count ticking up to 1, and then back down to zero on my Samsung SSD.  The SSD was quite old and too small for my current needs, so I just replaced it with a new Crucial SSD.  The problem persisted with the new drive, so I replaced the SATA cables.  Unfortunately, it still hasn't gone away.  I've tried both 6Gb/s ports on my motherboard, and I get the same issue on both of them.  The cables are not routed with a bunch of other cables (that is, they're not all zip-tied together).

 

Is this some kind of controller failure?  Should I connect the drive to one of the slower SATA II ports and see what happens?  I'm at a bit of a loss as to what could cause this.  Thanks!

 

Diagnostics attached.

hyperion-diagnostics-20180903-1356.zip

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@Gizmotoy I can't say why it happened on your Samsung SSD, but, I do know that certain Crucial SSDs have a firmware bug that causes this behavior. 

 

I have a Crucial M500 SSD as an unassigned device for VMs and I see this issue quite frequently.  Current Pending Sector Count is reported as 1 and then a little while later returns to 0.  As I researched the cause, it was reported in Crucial forums as a firmware bug and not a cause for concern. 

 

Here is an unRAID user report of the same issue:

 

 

Keep an eye on it.  If it ever goes above 1, then perhaps there is an issue with the drive itself.

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It is indeed an MX500, and also used with the Unassigned Device plugin.  Assuming it is the device, did you find a way to silence the warnings?  It varies in frequency, but it seems like I got 30 emails about it yesterday.

 

I'm still a little worried because the Samsung 830 it replaced was doing the same thing.

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Is your MX500 running the latest available firmware? 

 

Virtually all reports of this issue are with Linux systems.  It does not seem to occur with Windows or MAC OSes.  If you got 30 notifications in one day, yeah, that's a lot.  One way to make the notifications less frequent is to acknowledge the error in the GUI.

 

As seen in the screenshot below from the Dashboard, on the "Smart Status" row there will be a triangle warning symbol. for the drive  If you click on that and acknowledge the error, it will go away for a while.  I last acknowledged the error a couple of weeks ago and just received a warning notification about pending sector count on this drive again today.    After acknowledging the warning, it will eventually return (this is good so it can be checked again), but, in the meantime monitor the drive SMART reports to see if there are other issues or if the count increases.  There may be issues with the drive.

 

image.png.6180d67b8dfd0bd9991c0847b78acdad.png

 

Once you acknowledge the error, SMART status returns to OK.

image.png

 

My current cache drive is an old Samsung 830 that has been in use in my main unRAID server since 2012.  I have not ever had this issue on that SSD.  Perhaps other brands/models of SSDs will have the same "error" that is only seen in Linux systems.

 

I wish I had a resolution for you other than ignoring the warning, but, that has worked for me and I have never seen any other issues with the drive in the SMART reports.

 

Edited by Hoopster
SMART warning returned and I updated the screenshot and explanatory text
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  • 4 weeks later...
13 hours ago, johnnie.black said:

You can disable monitoring that attribute just for the SSD for now, no point to keep receiving false alerts.

I tried to find the option to do this, but I didn't have much luck and am drowning in these alerts.  If I use the Acknowledge process Hoopster described earlier, but the acknowledgement seems to get cleared as soon as the count returns to zero.  Then when it ticks back up to 1 I get the alert again.  Disabling for this attribute on this drive would be great, if possible.

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1 hour ago, johnnie.black said:

On the main page click on the SSD, scroll down to SMART settings and untick attribute 197

Ah, I see.  It's only available for array drives.  This disk is mounted through Unassigned Devices, and it looks like drives not in the main array lack the ability to disable monitoring. Bummer.  Maybe there's a workaround?

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7 hours ago, Gizmotoy said:

Ah, I see.  It's only available for array drives.  This disk is mounted through Unassigned Devices, and it looks like drives not in the main array lack the ability to disable monitoring. Bummer.  Maybe there's a workaround?

Yes, only array and cache devices, I believe there's no way for now to do that for unassigned devices.

 

You could probably get around it by disabling 197 on the general SMART settings, and then enable for all array/cache devices, though it will stop monitoring other unassigned devices, if you have some.

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On 9/30/2018 at 12:38 AM, johnnie.black said:

Yes, only array and cache devices, I believe there's no way for now to do that for unassigned devices.

 

You could probably get around it by disabling 197 on the general SMART settings, and then enable for all array/cache devices, though it will stop monitoring other unassigned devices, if you have some.

Thanks.  This seems to have worked until Crucial has a fix.  Though I'm a bit worried they'll never fix it.

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  • 9 months later...
On 9/3/2018 at 10:37 PM, Hoopster said:

Is your MX500 running the latest available firmware? 

 

Virtually all reports of this issue are with Linux systems.  It does not seem to occur with Windows or MAC OSes.  If you got 30 notifications in one day, yeah, that's a lot.  One way to make the notifications less frequent is to acknowledge the error in the GUI.

 

 

Is this bug still known?

 

And I have Windows 10 and I experince this, around once rarely twice a day it does to 1 then around 1 minute later it goes back to 0 so this bug exist outside Linux if its still there.

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4 hours ago, Nimras said:

And I have Windows 10 and I experince this, around once rarely twice a day it does to 1 then around 1 minute later it goes back to 0 so this bug exist outside Linux if its still there.

Yes, it's still a bug and, yes, reports of it are now popping up if the SSD is installed in a Windows PC whereas it used to be only Linux users that saw it.  The only "permanent" fix, at least in unRAID, is to disable reporting of SMART attribute 197 - current pending sector count.

 

image.thumb.png.a3c764e92f80c5226deeeb0a29682062.png

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  • 2 months later...
14 hours ago, johnnie.black said:

according to Crucial is normal

Crucial customer:  Hey, Crucial, I keep getting "current pending sector count" errors on my brand new MX500 SSD and then the error just seems to go away until it pops up again at another time.  It's very annoying and has me worried that my SSD is failing.  Can you please fix that?

 

Crucial: Ummm...we have no idea what is causing it or how to fix it, and, now that it is popping up on multiple operating systems, we really don't want to take the time to resolve it; therefore, we are declaring that this "error" is completely "normal" and you really should not be worried about it.  

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Yeah, this is the actual bullshit answer from Crucial support, it was posted by a FreeNAS user with the same problem on their forum:

 

Quote

Thank you for contacting Crucial Support.


The pending sector attribute is legacy number from traditional HDDs, where there could be multiple blocks pending because they’re quite slow at processing them. SSDs on the other hand are expected to have a pending sector at any given time, as this is its natural way of evaluating if a sector can be corrected or should be retired.

So the number you are seeing is entirely normal and should be ignored if any utility is flagging it.

 

 

Which begs the question, if it's so normal why don't other Crucial models have this issue?

 

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  • 3 months later...
  • 3 weeks later...
Just had this happen about a week after installing an MX500 as a cache drive.  Guess it’s here to stay, at least I (and anyone else that finds this thread) know it’s an expected issue and not indicative of an early drive failure.  
Im having same issue within 48 hours of swapping my Crucial 240GB SSD...

Got mine in July but only installed now, will update firmware but will try to get RMA

Sent from my SM-G973F using Tapatalk

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Im having same issue within 48 hours of swapping my Crucial 240GB SSD...

Got mine in July but only installed now, will update firmware but will try to get RMA

Sent from my SM-G973F using Tapatalk

Ha! Already on latest firmware will see if I can send back but doubt I will get a response from seller on ebay.

Sent from my SM-G973F using Tapatalk

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9 minutes ago, bally12345 said:

Ha! Already on latest firmware will see if I can send back but doubt I will get a response from seller on ebay.

Sent from my SM-G973F using Tapatalk
 

Fortunately, the "error" is not usually indicative of an actual problem with the drive.  Many of us have used MX500 SSDs for years and simply disabled reporting of this attribute so we don't get nagged by it.  Of course, that means the SSD could at some point develop a bunch of pending sectors and be failing and you would never know.

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20 minutes ago, Hoopster said:

Of course, that means the SSD could at some point develop a bunch of pending sectors and be failing and you would never know.

Yes, but SSDs rarely get pending sectors, most times when they fail they were working good, you reboot, it's gone.

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Yes, but SSDs rarely get pending sectors, most times when they fail they were working good, you reboot, it's gone.
This SSD feels so painfully slow! I'm sure there is something wrong with it... Is there any simple test I can do just to write to the disk and see the speed?

My Win10 VM is pretty much griding to a halt... And for some reason after restore appdata using CA plugin and moving all my system /domain folders to back to cache using PREFER in share settings I have had to redo my dockers but pulling them is taking forever...

Sent from my SM-G973F using Tapatalk

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100% something not quite right, tried a quick check in Sabnzbd which all download write to cache and it seem to bottleneck around 7MB/s compared to the 45MB/s I normally get also the pystone score seems very low

 

System performance (Pystone)5911  Intel(R) Xeon(R) CPU E564…
Download folder speed11.5 MB/s  (/data/incomplete)
Complete folder speed8 MB/s  (/data/completed)

 

server-diagnostics-20200113-2331.zip

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