I got this drive from a friend which, after installing some utility to monitor disk status, got warnings about the health of this disk… so he gave it to me to perform tests and helping him on what to do with this drive.
He didn’t noticed any strange behaviour during normal daily use, and the disk was already emptied so I can make any test I wish without worries about the data… and there’s still more than a year of full warranty.
so… I understand there where 3 UNC, which the offline scan took care of, probably remapping them and there where some read/write errors I should not worry (or should I?)… but how to read that huge number of Current Pending Sectors?
So far I already did, using Data Lifeguard (DOS boot), a full zero write, short and extended tests… in this exact order. All of them finished with no errors, but nothing changed in the SMART values.
I made an extra full write-read session using HD Tune, from Windows, but still nothing changed.
How it’s possible?
I don’t think an RMA would be accepted on that basis, but I don’t feel confident telling that this drive is safe to store data…
have you got some hint on what to do, other type of testing method/utility to suggest or what?
actually I’m finishing a full format from O.S. and tomorrow I’ll fill the drive making a full file copy to fill the whole 2TB space, so I can have other info from the higher layer side… probably it won’t solve anything but at least I should have more detail in case of a last resort WD assistance call.
for coincidence, hd sentinel is the same program i use on my personal PC to control my HDDs health.
Here’s some screen:
As you can notice, after finishing the full format and file copy (I finished just yesterday filling the whole 2TB space), the value of UNC from offline scan dropped to 0 (good news I think… I didn’t even know that this value could change), and the write error rate is lower too. No change in other values.
Actually I’m finishing a (loooong) read-write-verify session, that will refresh the data actually stored on it, forcing again another full rewrite of the disk surface… then I will get checkums of the files stored and compare them to the original ones to be sure no real errors are made in the process.
But I confess that if everything goes fine and get no changes in the pending sectors counter (what I fear and expect), I’ll be a bit confused about how interpret the SMART data.
Can it be so wrong and how can I trust the other data it’s collecting? Is there some one-time event that could have screwed it (power surge, a bad shutdown or similar)? … so far the disk is performing fine in every test and normal-stress use conditions I’m recreating.
After this last test I think I’ll going to submit the “case” to WD Help and check what they suggest to do.
I’m not really sure of what’s really happening… but agree that the drive can’t be called “good”.
I mean, if the sectors were remapped there should be trace in reallocated sectors/event count… but they’re all zero.
And those pending sectors keep pending even after a fair number of full disk rewrite and verify… so I would expect to see errors somewhere, but the drive keep performing apparently fine.
I too would be happy to RMA it, but I’m not sure WD will accept… think it’s time to check their customer service and get some advice.
Considering all other signs of disk health are perfect - as a programmer it is my guess that the number of pending sectors has somehow gone negative. There is code in the firmware to reduce the number of pendings when appropriate - i have seen this happen on my WD’s - so it is probably a firmware bug or some glitch. Assuming the pending is stored in a two byte unsigned number, if it was zero and 1 is subtracted from it, will turn into 65535.
Still I think you are right to RMA it, and that it was nice of Bill to suggest that.
I’m glad you got good help in this thread. You obviously took the time to investigate the drive to verify whether or not you had a valid cause to be concerned, and we appreciate that too. I’m glad you decided to go for a replacement. In the end, it’s your data that you have to be comfortable storing on the drive.
