MHDD remap and SMART values

[weaker]

After I encountered some kind of application stall while accessing certain data, I let HDDscan perform a surface test of my Raptor 74GD (2nd gen).
It reported some LBAs as slow and some as bad. I checked the SMART values of the disk and found "reallocated sector count" and "reallocated sector event" both as 0.
Now I booted into MHDD and had a scan with remap enabled. (Not the whole disk but starting in the proximity of the reported LBA values). MHDD also found slow sectors and UNC sectors. I assume MHDD triggered some remapping (or did something) because afterwards I can scan the whole disk in MHDD without slow or UNC sectors.
What puzzles me is when I looked at the SMART data after using MHDD: "reallocated sector count" and "reallocated sector event" still remain as 0.
("Uncorrectable errors count" however is != 0).

Can someone tell me, what happened here? Why didn't the reallocation counter increase? Did MHDD trigger remapping or did the sectors come back to life after several tries and are not remapped? Is the SMART counter only increased if a SMART testing routine remaps the sector?

I know that bad sectors are sign of imminent failure of the disk and already have ordered a replacement. I just wanted to make sure that the disk lives until the replacement arrives.

[weaker]

Did I pose my question somehow vaguely? Do you need additional information? I thought that the pros here could answer that question blindfold...

[ppumkin]

Missed your post.
Best thing todo is do a full erase of the drive in mhdd. use ERASE.
Then do a full scan afterwards. See what the results are.
Its possible the sectors got "relocated" but it does not always have to show on smart. Check smart after erase too.
Some hard drives support functions to discretely relocate slow or unc sectros- others don't and will just stop on UNC and that's it.

[weaker]

Thank you!
So it is not defined that a drive has to report a relocation in its SMART values? That's interesting.

When I finished transferring the data to a new drive I will do a full erase. Should I do that inside MHDD or in with the manufacturer's hard disk tool? Is there a difference? Often I use hddguru's LowLevelFormat running in Windows. That way I can use the PC for other tasks while it is wiping.

[pclab]

yeah you could use MHDD to secure erase or HDDerase hdderase-t9993.html

[weaker]

But would that make a difference regarding the remapping of bad sectors? Does the manufacturer's tool anything different than the other tools regarding the remapping process?

[pclab]

That does a full erase, no remaping.

[ppumkin]

Erase is filling the sectors with data. either 00 or 11 or AB from 0 to max. If you use mhdd or the manufactueres version or the windows version it all the same.
For simplicity and less variance in problem solving stick with one program.
Run ERASE
Then you need to run scan + remap.

SMART is very interesting- i agree.

It might fix it but its not a guarantee.
The manufacturers tool can has extra options to run SMART scans- it would be good todo those and as a rule of thumb its better to use the manufactures tools todo that as their program knows how to run the program. Mhdd's can also do this.. but it is limited sometimes and does not alwyas do what it should.(out of the box to speak)

Please read the attached document and try and do a bit more research into what erase does and how it can help with the process of remapping sectors. Sometimes slow sectors or UNC are not actually there... that's why you don't have a relocate. And you can only find this out after ERASE. I will not go into detail.
All this info is freely available on this forum and wikis world wide.

Attachments

MHDD-alternative manual (1).pdf

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[weaker]

Thank you again. I will read into the document to better understand what is going on.