MHDD drive tests to 99.99%

[spindleman]

I have several hard drives which test without error but they do not reach 100% completion. The drives test until the progress indicator reaches 99.9% and then the test exist as if it reached 100%. Most of these "99.99%" drives have given me a hard time in various circumstances, so I believe that there is something relevant about these drives which do not reach 100%.

Has anyone else experienced this?

[BlackST]

Yes, then the drives will be repaired.

[spindleman]

What is the procedure for repairing the drive with MHDD?

[BlackST]

Not with MHDD of course. Would be too good to be true.

The only thing you can do with MHDD (loosing every data on it) if the problem is simple, is ERASE : Erase the drive.

[spindleman]

Do you have a recommended software tool for repairing the portion of the drive which is causing the scan to exit at 99.99%?

I'm pretty sure that we tried low-level formatting at least one of the "99.99%" drives and MHDD still tested them the same afterwards.

We would have used this tool to low level format

http://hddguru.com/software/2006.04.12-HDD-Low-Level-Format-Tool/

[spindleman]

Has anyone else experienced this, or have any input on how to correct this issue?

[harddrivespecialist]

You should explain what type of scan you are doing and what type of drives you are trying to repair?

[BlackST]

Has anyone else experienced this, or have any input on how to correct this issue?

The procedure you are using is NOT a repair procedure, it's a cosmetic solution. The complete solution/s requires know how and dedicated equipment. However, your procedure works for end users and for simple problems.

[spindleman]

You should explain what type of scan you are doing and what type of drives you are trying to repair?

We are launching MHDD and doing a default scan (Select drive number, F4, F4)

The drives are mostly SATA drives from various manufacturers, mostly Western Digital "raid edition" drives but also some Seagate, Fujitsu, etc. We have also seen a few IDE drives test this way.

The test runs to completion and MHDD looks like it passed the drive, however the progress indicator says 99.99% complete instead of 100%. At first we thought it was just some type of mathematical error within MHDD, but then we started to notice a pattern. If we put one of these "99.99%" SATA drives into a RAID1 array and tell the array to synchronize, the drive inevitably drops out of the RAID array.

We have sent a few of these "99.99%" drives back to the manufacturer and they claim there is nothing wrong with them, yet the drives will not stay in a RAID array for any length of time. The hard drive diagnostic software tools provided by the hardware manufacturer generally pass these drives, but those same tools also pass drives that MHDD fails so we feel that the manufacturer provided tools are a bit more "forgiving". MHDD has proven itself to us to be a good benchmark as to if a drive is good or bad, other drives which MHDD fails (UNC errors, >500ms sectors, etc) are generally replaced by the manufacturer without question.

We wish to find out what is causing these drives to test differently from other drives. Presumably that is also the reason that causes the drives to drop out of RAID arrays. Once we know what the problem is, we hope to determine if its something that could potentially be fixed by means of a software tool (perhaps some type of sector remapping, low level formatting, etc).

These drives have been pulled out of service and the data we care about has already been moved off of them, so we do not mind running routines on the drive which may be considered destructive in regards to existing data, partitions, etc.

[BlackST]

I do refurbishing drives and it's completely different thing. After refurbishing drives are like brand new, all defects relocated and 100% surface clean, no delays, ZERO user level visible defects, all parameters tuned, SMART reset and everything else reconfigured...
The only thing is that the drive has worked "n" hours. Of course it is not possible to do it via simple software.
Also, it is a time consuming procedure and usually it is applied to "x" drives at same time, otherwise it wouldn't be convenient (well, if you have a small batch it can be done too).
There are some kind of errors that lead simple software tools like MHDD or the mfg's so-called "tools" (nothing more than MHDD in almost totality of case) to hang or emergency exit.
Usually it is possible to do something : anyway, if you want specific know-how about fixing / refurbishing drives it's not for free, otherwise use MHDD and co. and reject the drives that fail.

[spindleman]

There are some kind of errors that lead simple software tools like MHDD or the mfg's so-called "tools" (nothing more than MHDD in almost totality of case) to hang or emergency exit.

Thats the strange part. MHDD does not throw an error nor does not hang, it exits exactly as if the test wa sa sucess however it says 99% instead of 100%

Usually it is possible to do something : anyway, if you want specific know-how about fixing / refurbishing drives it's not for free, otherwise use MHDD and co. and reject the drives that fail.

I respect that knowledge about how to completely refurbish a drive is likely to be complicated and require special software and/or equipment. If that is the case then its probably outside the scope of what we want to do in order to be able to reuse the drives.

Backing up for a moment, does anyone know what causes this? Is completely refurbishing the drive the only solution?

[drc]

What exactly is the problem that you are having? I know about the stopping at 99.9% issue but what secondary indications are you having that there is something wrong?

Maybe this is just a software bug related to the way it divides the total LBA into percentages?

[spindleman]

...what secondary indications are you having that there is something wrong?

If we take one of these 99.99% drives and put it into a RAID 1 array, inevitably it will drop out of the RAID array during synchronization.

[BlackST]

Backing up for a moment, does anyone know what causes this? Is completely refurbishing the drive the only solution?

Cause : unrecoverable (by you) bads on disk and/or problems on reading some parts (out of specs for access time for example) that make controller think that the drive has problem = drop it out.

Is complete refurbishing the only solution ? Yes. The drive comes back as-new if you don't consider the wear of mechanical parts , ZERO defects.