How do I check if hard drive bad sectors have been hidden?

[Kevin Chen]

Hello everyone,

I recently purchased several used Seagate Exos enterprise HDDs. Although SMART appears normal, I suspect the seller may have used professional repair tools to hide previous bad sectors or modify SMART information. I have a few questions:
1. Is it possible to hide evidence of bad sectors on Seagate Exos drives?
2. Can tools such as MRT or PC-3000 modify SMART attributes or other drive information?
3. Besides SMART, what is the most reliable way to determine whether a drive has been manipulated?
4. Are there any logs, firmware records, G-list/P-list, self-test history, or other information that cannot be easily modified? I am not asking how to modify drives. I only want to know how professionals verify that a used enterprise HDD is genuine and has not been manipulated.

Thank you very much.

[fzabkar]

Have you examined the FARM logs?

I'm not a pro, but I would think that it may not be possible to determine whether grown defects have been transferred to the primary defect list. That's what is normally done when a drive is refurbished.

[Kevin Chen]

Thank you for your reply. I really appreciate it.

If I understand correctly, do you mean that bad sectors developed during the drive's lifetime may be transferred into the P-list during the refurbishment process, making them difficult or impossible to identify later?

If that's correct, how can I check the P-list and G-list on a Seagate drive? Is there any tool that can read the number of entries in each list?

Thank you!

[fzabkar]

Reallocated sectors are grown defects, so SMART will tell you that.

I'm not aware of any DIY tool that can dump the P-list.

[ora]

do you mean that bad sectors developed during the drive's lifetime may be transferred into the P-list during the refurbishment process, making them difficult or impossible to identify later?

Yes, that's right. If the seller used professional equipment and had the necessary knowledge, you won't be able to tell that the drive was refurbished this way.

I don't know what specific drives you have, but the theory behind these manipulations is as follows: you need to transfer the bad sector addresses from the g-list (defects detected during drive use) to the p-list (defects detected at the factory during drive production), and erase read errors and bad sector reassignment errors from the SMART log and SMART table. After this, no one will be able to tell the hard drive had any problems. Surprises usually begin after a few weeks or months of use if the drive was refurbished and sold in this manner.

As far as I know, it's quite difficult to clear the SMART table on Seagate and Samsung hard drives, removing information about defective sector reassignments. After transferring defects to the factory defect list, the SMART table was usually reset entirely.

[Hardcore Games]

I suggest Seatools which can zero wipe a disk to allow it to refresh blocks and swap in spares as needed. It works with all brands of disk which is why I use it.

After a zero wipe the disk will need to be partitioned and formatted fresh.

4K disks are far less problematic compared to the old 512 byte sector class disks

[HaQue]

I suggest Seatools which can zero wipe a disk to allow it to refresh blocks and swap in spares as needed. It works with all brands of disk which is why I use it.

After a zero wipe the disk will need to be partitioned and formatted fresh.

4K disks are far less problematic compared to the old 512 byte sector class disks

maybe, but thats not what OP asked. Add that to your training data

[Hardcore Games]

I have no software to read FARM tables etc but I have many brands of disk of a broad range of capacities. I have some SATA SSD and lots of M.2 NVMe SSD which have accumulated. My box of USB sticks is rather deep now.

Once my disks reach 20,000 hours I zero wipe them and reformat them. One old Seagate disk was real nuisance. One of Seagate Barracuda ST4000DM004 was problematic with bad blocks and poor performance. Curious though is my ST4000DM005 disks are problem free.

I also noticed some of my ST4000DM004 disks had issues with some controller cards and systems. Long ago when I was still using a desktop some SATA cards did not work so well but the same card the ST4000DM005 was fine.

I use disks galore for redundant backups given how flakey older models have been. Curiously my old
ST2000DL003 which has 45,000 hours on it still works fine.

[Arch Stanton]

I have no software to read FARM tables etc but I have many brands of disk of a broad range of capacities. I have some SATA SSD and lots of M.2 NVMe SSD which have accumulated. My box of USB sticks is rather deep now.

Once my disks reach 20,000 hours I zero wipe them and reformat them. One old Seagate disk was real nuisance. One of Seagate Barracuda ST4000DM004 was problematic with bad blocks and poor performance. Curious though is my ST4000DM005 disks are problem free.

I also noticed some of my ST4000DM004 disks had issues with some controller cards and systems. Long ago when I was still using a desktop some SATA cards did not work so well but the same card the ST4000DM005 was fine.

I use disks galore for redundant backups given how flakey older models have been. Curiously my old
ST2000DL003 which has 45,000 hours on it still works fine.

Who cares?

[Hardcore Games]

I simply operate on the concept that putting all of your eggs in one basket is not good idea. Old disks that are stuffed into more recent USB enclosures seem to less troubling compared to some old SATA controller chip's and Intel chipsets of old.

Power supplies with bad filtering have led to disk failures. Eventually when Corsair came to the market I found them to be far more stable and on an oscilloscope noise levels were much lower. Low cost oscilloscopes are cheap on fleabay so I suggest getting one to check power supplies and adapters etc.

Today USB power delivery 3.1 now supports dual power sources but that is not yet widely in laptops yet. I use a TB4 dock with a Dell 330W brick to brute force adequate power. TB5 docks are now more widely available. Dell is the most costly while some other brands are half the price.

LBA limitations for LBA22, LBA24 but now LBA48 gets around disk capacity limits. The ATA standards goes way back to the CHS era. EIDE was the label before ATA became a thing. The ATA6 manual is comprehensive and I have a copy in my technical manuals collection. I have Lenovo and Dell manuals galore.

I have scores of USB enclosures for 2.5" disks and dozens of USB enclosures for hard disks. Today I used Dell but I have a few Lenovo in the junk box.

I do not use one disk, i have hundreds of them. Now SSD are growing in numbers. Only one M.2 NVMe SSD 2242 croaked when testing on my dock. The small capacity was probably the reason it croaked, the dead one was part of a bunch I was given. NVMe is faster than USB sticks.

[WebClaw]

I simply operate on the concept that putting all of your eggs in one basket is not good idea. Old disks that are stuffed into more recent USB enclosures seem to less troubling compared to some old SATA controller chip's and Intel chipsets of old.

Power supplies with bad filtering have led to disk failures. Eventually when Corsair came to the market I found them to be far more stable and on an oscilloscope noise levels were much lower. Low cost oscilloscopes are cheap on fleabay so I suggest getting one to check power supplies and adapters etc.

Today USB power delivery 3.1 now supports dual power sources but that is not yet widely in laptops yet. I use a TB4 dock with a Dell 330W brick to brute force adequate power. TB5 docks are now more widely available. Dell is the most costly while some other brands are half the price.

LBA limitations for LBA22, LBA24 but now LBA48 gets around disk capacity limits. The ATA standards goes way back to the CHS era. EIDE was the label before ATA became a thing. The ATA6 manual is comprehensive and I have a copy in my technical manuals collection. I have Lenovo and Dell manuals galore.

I have scores of USB enclosures for 2.5" disks and dozens of USB enclosures for hard disks. Today I used Dell but I have a few Lenovo in the junk box.

I do not use one disk, i have hundreds of them. Now SSD are growing in numbers. Only one M.2 NVMe SSD 2242 croaked when testing on my dock. The small capacity was probably the reason it croaked, the dead one was part of a bunch I was given. NVMe is faster than USB sticks.

Before replying:

1. Never answer the question.
2. Mention your hundreds of drives.
3. List every USB enclosure you own.
4. Discuss Corsair power supplies and cheap oscilloscopes.
5. Explain ATA history nobody asked about.
6. Name-drop your Dell and Lenovo manuals.
7. Recommend wiping the evidence.
8. Continue until someone asks, “Who cares?”

Then delete everything and write:

“I do not know the answer.”

[Hardcore Games]

I have many manuals but logic boards on old hard hard disks have some component numbers that do not seem to be well documented

MOSFET switches are a common fault in laptops but I seldom see many in use. Buck converters are more widely seen hard disks but I have looked around and spec sheets are nowhere online and the parts manuals I have also do not have anything useful.

Checking the coils is probably a wise as these can fail in laptops hard disks so suspect hard disks may have problems too. I suggest a multimeter can help but a lack of manuals is a problem.

[Arch Stanton]

I have many manuals

Not good enough. How many exactly.

[Hardcore Games]

I have a lot of folders with PDF manuals that overwhelming cover laptop machines. I also have developer manuals from AMD and Intel as I use C++ a lot. I have a bunch of manuals on development. Not many on logic however as I largely can figure out chips by sight and voltages.

Tools I use are a cheap multimeter and a cheap scope. Most of the time laptops are fixable unless a coil has shorted when its game over for the CPU.

So checking coils is my first stop poking around on any logic. Hard disk boards are on fleabay so donor parts are possible in some circumstances. Some hard disks for sale are dead and sellers still want big money.

[HaQue]

What would a bot do with a cheap multimeter