Accidentally used an EVGA sata power cable on a phanteks PSU for 3 hard  drives. Unraid server wouldn't power on on multiple tries. Then I  realized my mistake and swapped to a correct cable, now BIOS and unRaid can only see 1 of 3 drives. They are both data drives with another data drive and parity intact.

 

I'm no disk expert so I have to ask, would it work if I have an expert clone the dead drive onto a new identical readable drive? Is there a way for unRaid to recognize that "new" drive as a replacement for the data drive with the exact same data?

Yes, by doing a new config.

57 minutes ago, JorgeB said:

Yes, by doing a new config.

Ok, thanks! Since two disks failed, I'm attempting to clone one then do a rebuild on another new drive to "replace" the second drive. Crossing my fingers that the cloning works.

If you succeed post back and I'll post the complete instructions, cloned disk needs to be the same capacity of the previous one, and the new replacement same or larger size.

Old thread - I know, but I'm more or less in the same situation.

 

I have 2 failed disks and only 1 parity. An expert checked them and says he might be able to clone one of them. if so, will Unraid then recognize the clone as the original disk so I can rebuild the other failed disk using parity and the clone (with the remaining good disks also)?

 

@JorgeB: Could you perhaps guide me in how exactly I would go about this in the interface? - and are there anything I need to inform the expert about, regarding the cloning process etc.

 

Thanks in advance.

If you can get one clone, you can then try this:

 

-Tools -> New Config -> Retain current configuration: All -> Apply
-Check all assignments and assign any missing disk(s) if needed, including the clone and new disk you want to rebuild, clone must be the same capacity as the old one, replacement disk can be same size or larger than the old one
-IMPORTANT - Check both "parity is already valid" and "maintenance mode" and start the array (note that the GUI will still show that data on parity disk(s) will be overwritten, this is normal as it doesn't account for the checkbox, but it won't be as long as it's checked)
-Stop array
-Unassign the disk you want to rebuild
-Start array (in normal mode now), and post new diagnostics

1 minute ago, JorgeB said:

If you can get one clone, you can then try this:

 

-Tools -> New Config -> Retain current configuration: All -> Apply
-Check all assignments and assign any missing disk(s) if needed, including the clone and new disk you want to rebuild, clone must be the same capacity as the old one, replacement disk can be same size or larger than the old one
-IMPORTANT - Check both "parity is already valid" and "maintenance mode" and start the array (note that the GUI will still show that data on parity disk(s) will be overwritten, this is normal as it doesn't account for the checkbox, but it won't be as long as it's checked)
-Stop array
-Unassign the disk you want to rebuild
-Start array (in normal mode now), and post new diagnostics

If the clone is a "100% valid clone", is this then a guarantee success to restore the other missing disk? Like if this was the old disk?

 

1 minute ago, TreksterDK said:

Like if this was the old disk?

Yes, assuming parity is also valid.

Just now, JorgeB said:

Yes, assuming parity is also valid.

What does the "New Config" feature specifically do? Just lets you re-assign any disks or? Maybe I am just a bit worried here, sorry

 

I appreciate your help! - But could you perhaps show me some screenshots, to make sure I do this the right way. Never did this before, and just don't want to mess this up.

 

Also, any recommendation to the guy making the clone? He said: "A cloned disk from here is always a 1:1 full sector copy.". Is that good enough?

1 minute ago, TreksterDK said:

What does the "New Config" feature specifically do?

It is covered here in the online documentation accessible via the Manual link at the bottom of the Unraid GUI.  In addition every forum page has a DOCS link at the top and a Documentation link at the bottom.   The Unraid OS->Manual section covers most aspects of the current Unraid release.

2 hours ago, TreksterDK said:

I have 2 failed disks and only 1 parity

How did you get to that point? Do you have Notifications setup to alert you immediately by email or other agent as soon as a problem is detected?

 

15 minutes ago, TreksterDK said:

guarantee success

No guarantees. Too little information to really know how likely success is. After you have completed all the steps and posted diagnostics, we will see how successful it was, or if more work can be done to try to recover any more.

 

Do you have backups of anything important and irreplaceable?

36 minutes ago, trurl said:

How did you get to that point? Do you have Notifications setup to alert you immediately by email or other agent as soon as a problem is detected?

 

Here is the full story.

 

I recently started rebuilding my old Unraid server with a new case, power supply and hardware. This is the case and the PSU

 

• Case: JMCD 12-bay NAS rackmount from Alibaba
• PSU: Corsair SF750 (2024 version)

 

The case manufacturer recommends distributing power to the HDD backplane (MOLEX) across multiple rails and avoiding daisy-chained cables. So I ordered some custom cables for that purpose. I suspect one of these custom cables caused the two disks to basically fry, but I am not completely sure.

 

After encountering the problems, I switched back to the standard power cables (except for one single Molex cable – also custom), and all drives were recognized – except for the two drives that are broken (6TB Barracuda drives). I have tested those two in different ports and with different power/data cables on the new server, but they show no signs of life. They do not spin up and are completely silent, unlike the other drives which work fine across various configurations.

 

I also tried powering them directly via the motherboard using SATA power from the PSU, and with an older Molex-to-SATA cable (one without the 3.3V line) – still no response. They are not detected in Windows either, even in Disk Management. I tested other working drives from the server in Windows also – they show up fine (not as accessible drives in Windows, since they use XFS – but still visible), so I know the system is functioning properly now – just too late for those two drives. I even tried putting them back in the old server – still dead.

 

Both drives have now been inspected by a data recovery expert. He confirmed that they were both exposed to overvoltage. Each of them has two short-circuited diodes and two damaged resistors. Electrically, the repairs were straightforward, but unfortunately, both drives have additional issues.

 

One drive now spins up but never becomes ready. It has damage to the preamp circuitry and reports failure in the read/write heads, which would require a head swap. That would make the drive readable only by specialized equipment.

 

The other drive does not spin up and reports a ROM code error. The expert believes the ROM issue can likely be corrected, and if that is the case, it might be possible to make the drive operational again. However, it is unknown if it also has preamp damage.

 

The expert said that the cost will be the same regardless of which repair option I choose. At the moment, I am considering going with the clone option, as he believes that offers the best chance of getting a functional drive.

 

This is why I wanted to make sure I could use that cloned drive as "the original drive" to restore the other drive. I will also replace the cloned drive afterwards with a bigger drive.

 

I have some backup, but not everything. It's 12TB of data. A lot of it is unimportant, but some of it is photos etc.

1 hour ago, TreksterDK said:

one of these custom cables caused the two disks to basically fry

There is no standard pinout for modular PSUs. Using cables that didn't come with the PSU seems to be what happened when someone fries disks.

1 hour ago, JorgeB said:

-IMPORTANT - Check both "parity is already valid" and "maintenance mode" and start the array (note that the GUI will still show that data on parity disk(s) will be overwritten, this is normal as it doesn't account for the checkbox, but it won't be as long as it's checked)

I guess that the array then starts to rebuild the other broken disk from: parity, the functioning drives and the clone of the other broken drive, right?

 

Sorry I am just a bit uncertain here, because in the next part you mention:

 

1 hour ago, JorgeB said:

-Stop array
-Unassign the disk you want to rebuild
-Start array (in normal mode now), and post new diagnostics

 

By "Unassign the disk you want to rebuild", do you mean the "clone disk" that I also want to rebuild afterwards? Or?

 

I just want to make 100% sure i do this right.

Just now, TreksterDK said:

I guess that the array then starts to rebuild the other broken disk from: parity,

No, not yet. At this point, if it actually starts to rebuild anything you have made a serious mistake.

1 minute ago, TreksterDK said:

By "Unassign the disk you want to rebuild", do you mean the "clone disk" that I also want to rebuild afterwards?

You don't want to rebuild the cloned disk. You want to be able to use the cloned disks with all the remaining disks to rebuild the missing disk.

Just now, trurl said:

You don't want to rebuild the cloned disk. You want to be able to use the cloned disks with all the remaining disks to rebuild the missing disk.

Yes I get that. It's because I said I also wanted to replace the cloned disk afterwards, because it is too small anyways.

Edited March 25, 20251 yr by TreksterDK

Let me break this down so you will maybe understand what we hope to accomplish. Nothing I say below has anything to do with a possible future rebuild of the cloned disk. If the cloned disk is working well it shouldn't need to be rebuilt. This is all about trying to rebuild the missing disk.

2 hours ago, JorgeB said:

Tools -> New Config -> Retain current configuration: All -> Apply

After this, the array assignments have been reset, but it will take the assignments already made (retained) as a starting point.

 

2 hours ago, JorgeB said:

Check all assignments and assign any missing disk(s) if needed, including the clone and new disk you want to rebuild, clone must be the same capacity as the old one, replacement disk can be same size or larger than the old one

You will complete the disk assignments here. The cloned disk will be included in the new assignments, and the disk intended to replace the missing disk will be included in the new assignments.

 

2 hours ago, JorgeB said:

-IMPORTANT - Check both "parity is already valid" and "maintenance mode" and start the array (note that the GUI will still show that data on parity disk(s) will be overwritten, this is normal as it doesn't account for the checkbox, but it won't be as long as it's checked)

Usually, New Config will rebuild parity based on all the other disk assignments. When you check the parity valid box, it won't rebuild parity but will just assume parity is OK and in sync with all the other disks. You also check maintenance mode so none of the disks are mounted, so none will be changed. Then starting the array accepts the disk assignments you have made.

 

2 hours ago, JorgeB said:

-Stop array
-Unassign the disk you want to rebuild
-Start array (in normal mode now), and post new diagnostics

This will disable the disk that you want to rebuild, and emulate its contents from parity plus all the other disks. Diagnostics will tell us if the emulated disk is mountable so its files can be accessed. The emulated contents are exactly what will be rebuilt.

 

If the emulated disk is not mountable, perhaps more can be done (filesystem repair) to make the emulated disk mountable before rebuilding it.

 

 

Just now, trurl said:

emulate its contents from parity plus all the other disks

https://docs.unraid.net/unraid-os/overview/nas/#parity-protected-array

1 hour ago, JorgeB said:

clone must be the same capacity as the old one, replacement disk can be same size or larger than the old one

but replacement disk cannot be larger than parity

Clone must be same size as the disk being cloned. The disk to replace the missing disk must be the same size or larger than the missing disk, but not larger than parity.

3 hours ago, TreksterDK said:

An expert checked them and says he might be able to clone one of them.

Of course, all we have said is getting way ahead of the game. You need the cloned disk (and a replacement for the missing disk) first.

25 minutes ago, trurl said:

Of course, all we have said is getting way ahead of the game. You need the cloned disk (and a replacement for the missing disk) first.

 

Yes. You are right. I just want to make sure it is possible before I ask him to do the work (It is not cheap )

 

So, thank you all for the help so far.

 

I never did this before. I have restored other disks previously from parity, but this - using a new config, is new to me. So, just to make sure I fully understand the correct process before I proceed (when I get the cloned disk):

 

The situation:

• I have 2 failed data drives and 1 working parity drive (8TB)
• My data recovery expert will create a 1:1 sector clone of one of the failed drives on a new 6TB identical disk (I will make sure I note which of the disks it is a clone of)
• My goal is to use that clone + parity + remaining drives to rebuild the second failed drive (on a new 8TB disk)

Based on what you said, here is how I understand the process:

• Go to Tools > New Config, select Retain all, and click Apply
• Reassign:
  • The cloned disk into the same slot as the original failed drive
  • A new replacement disk (the new 8TB drive) into the slot of the second failed drive
• Check “Parity is already valid” and “Maintenance mode”, then start the array (I don't know how much time is used here - what the system does?)
• Stop the array immediately again
• Unassign the replacement 8TB disk (so Unraid sees it as missing)
• Start the array (now in normal mode)
• Unraid should now emulate the missing disk (the other broken 6TB Baracuda drive). If it looks OK and diagnostics confirm it is mountable (I will send that here):
• Stop the array again, reassign the replacement disk, start the array, and let Unraid rebuild it

 

Is this the process? Is there anything I am missing or need to be extra careful about?

 

And again, thanks for all the support so far! I really appreciate it.

 

Edited March 25, 20251 yr by TreksterDK

I informed the expert to go ahead an create the clone (will take some days)

 

After that phone call I got concerned that the other disks in the array might have been affected by the overvoltage (that damaged the two 6TB Barracudas). So to be safe I ran SMART health checks and short self-tests on all of the remaining drives (parity disk plus four data disks) using the console.

 

All drives:

• Report SMART overall-health: PASSED
• Show zero reallocated or pending sectors
• Completed short self-tests without any errors
• Have clean logs (no UDMA CRC errors, command timeouts, or other warnings)

So as far as I can tell, everything appears healthy and unaffected 🤞

 

If there is anything else I should check or if you have any suggestions for other stuff to check while I wait for the cloned disk, I would very much appreciate it.

If you really want to check their health out you should run the long SMART test as any drive that fails that should be replaced.