Can Current Pending Sector Count be fixed permanently? (WD)

tonymaloney · 28 May 2016

Hey. I could goto the WD forums but I trust this forum more

I am an intermediate user however not with hdds. I will write my scenario in note form to cut down on blabber.

Random check on CrystalDisk revealed 1 Current Pending Sector Count on my 3 TB WD My Book External. Showed in HD Tune and WD Data Lifeguard Diagnostics too.
Ran error checking multiple times with all combination of ticks, following results each time:
1 CPSC showed on CrystalDisk, HD Tune and WD DLC, quick test passed on this.
1 CPSC showed on CrystalDisk, HD Tune and WD DLC, quick test failed, extended test failed (too many errors)
Ran chkdsk /r in command prompt
1 CPSC showed on CrystalDisk and HD Tune. No errors on WD DLC and both tests passed.
Zero wrote disk with HD Tune.
No errors shown in CrystalDisk, HD Tune, or WD DLC. The quick test passed and I am currently doing an extended test. (Could not wait any longer to post here haha)

So thats where im at now. Does this disk appear to be fixed then? Or (newb theory) will this error show up again once my disk tries to write to that sector?

Don't want to use the disk again if its just a short matter of time.

Many Thanks in advance

ignatzatsonic · 28 May 2016

I'm no expert either, but it would appear the bad sector has been sent to the sidelines and replaced by a good sector off the bench. That's why you are currently getting no errors.

Your hard drive has a fixed and limited number of good sectors on the bench.

However, you say "if its just a short matter of time."

I think it was Keynes who said, "in the long run, we are all dead".

He was right and that applies to your hard drive as well.

Reasonable people can differ on the meaning of and dividing line between "short matter of time" and "long run".

I've heard there is a tendency for one bad sector to be a sign and that you are more likely to develop new bad sectors than someone who never had the first bad sector.

Dunno if that's true.

It shouldn't matter. You should always assume your hard drive will fail completely in the next 10 seconds and know what you will do when that happens. When that happens, not if it happens. Because Keynes was right.

Digerati · 29 May 2016

will this error show up again once my disk tries to write to that sector?

It should not try to write to that sector again. Running chkdsk /r marks any bad sectors in the tables just so the interface does not try to use the bad sectors again.

This could be a one-time issue and all is good. But typically, once bad sector problems start to appear, it is not uncommon for more problems to appear. It is often like fixing a leak only to see 2 more appear.

Is the device still under warranty? If the WD drive fails WD's diagnostics and the drive is still under warranty, WD really has no excuse but to RMA it. If not under warranty, then you are on your own. In any case, no single drive should EVER be your only backup. So if me, I would probably start watching out for sales. I NEVER trust HDs that start developing problems.

RolandJS · 29 May 2016

I recommend buying two 1-3TB platter-driven external HDs for each computer you're backing up on a weekly or bi-monthly basis. I have two for each of my three computers -- and there have been rare times I'm glad I did have two for each!

Digerati · 29 May 2016

"Physical" security is something that should not be overlooked. If you have all your backup drives connected to your computer via USB, what happens if a fire, flood, hurricane or tornado takes out your home? You lose everything, including your backups. If a bad guy breaks into your home and steals your computer, he likely will take your external drives too. So again, you lose everything.

So I recommend "networked" drives (NAS) for backups because you can locate those in a different part of the house - even hidden in a closet. But you should also have an "off-site" solution too - either the cloud, an image disk at a neighbors, or in a safe deposit box at your bank.

RolandJS · 30 May 2016

I forgot to mention, all those external 1TB HDs I use for backups -- are put away, far away from fire or flood or theft :)

Digerati · 30 May 2016

RolandJS said:

I forgot to mention, all those external 1TB HDs I use for backups -- are put away, far away from fire or flood or theft :)

That's great! I tell folks if USB connected, it is best to disconnect and put away when not in use. If network connected, they can be physically located in a secluded place, away from other, attractive to bad guys, computer equipment.

LMiller7 · 30 May 2016

When an error occurs during a write to the drive the bad sector is replaced with one set aside for this purpose. This takes place internally by the drive and even the OS is unaware of it. For practical purposes the sector has been repaired.

Things are different when an error occurs during a read operation. Replacing the sector would not be a good idea because the contents of the sector is unknown and the problem cannot really be fixed. And if the sector was replaced it would be inaccessible and there would be no possibility of later recovering it's data. The error may have been due to a temporary condition.

In this case the drive makes note of the problem and increments the Current Pending Sector Count value. There are 2 situations where the problem can be fixed, neither of which is guaranteed to occur.

1. The sector is later written to with known data.
2. The sector is later read successfully.

In either case the sector can be replaced and it will cause no problems.

The problem is that the bad sector may be the first warning sign that the drive has internal problems. In that case the number of errors will tend to increase over time. This may take place slowly, or it may fail in a very short time.

For this reason (among others) you should always have a backup of all important data. Any drive, new or old, can fail suddenly without warning or apparent cause. I had one drive that was working fine one day, the next it wasn't even detected by the BIOS. As I had backups of everything important I did not investigate further.

SSDs typically fail without warning.

RolandJS · 30 May 2016

"...SSDs typically fail without warning." Yep, so can platter-driven HDs. I had one quit real quick like [it was my fault, earlier I collided with the chassis]. Another time, I got SMART warning, ok, sometimes weeks, sometimes days one has. Thankfully I backed up immediately, the HD began rapidly failing within a day.

For that reason [HD failure] Each of my computers has two dedicated usb external HDs receiving the full images of OS and data partitions. Also, HDs can fail "logically," while a format and re-partitioning often brings it back fully to life -- the OS [C] and the data [D] can be considered: gone to the boneyard.

townsbg · 30 May 2016

There are 2 causes for bad sectors. One, a problem with the file system. Windows will correct this if possible or mark it as bad and not use it again. Two, physical problems with the hard drive. Windows cannot fix that and that is likely the situation where it will mark the sector as bad. Now I don't know what CrystalDisk is but I would go to WD's website and download their diagnostics. Their diagnostics will do what windows cannot and tell you if there are problems with your drive. In that you case you should back up and plan on replacing the drive. Some physical issues may be fixed but only by an expert; it would be cheaper just to replace the drive. Some cannot be fixed. If it is still under warranty you should contact WD for a replacement.