Is it possible to rebuild a RAID 1 set with 2 degraded drives?

[PCohe1]

Dell T3600 with Intel C600 RAID controller:

I have a 2 drive RAID 1 configuration with both drives showing degraded. System is running with no apparent data loss. RAID set was degraded by booting into a unsupported configuration (attempted two RAID 1 sets on the controller.)

No "rebuild" option is showing in the ROM window. Is there a way to get the RAID 1 set to rebuild without wiping out the data on the drives?

[Alberto_R_Intel]

PCohe1, Thank you for posting in the Intel® Communities Support. Just to let you know, the Intel® C600 RAID controller is a chipset that you will find in server boards, that is why in this case in order to try to gather the information that you are looking for the best thing to do will be to get in contact directly with Dell, they should be able to provide all the details needed for your RAD configuration: https://www.dell.com/support/home/us/en/04 Regards, Alberto R. Intel Customer Support Technician Under Contract to Intel Corporation

[PCohe1]

This reply is not helpful for several reasons: If I intended to ask Dell, I would have asked Dell. I did not ask Dell because they would not answer the question due to: 1. The system is not under warranty. 2.They would only be able to answer from a script, so they would not actually know the answer.

I think my question was pretty straightforward. Is there a way to recover a RAID 1 set with no apparent data loss, if both drives are degraded.? That is not a Dell-specific question.

[Alberto_R_Intel]

Thank you very much for letting us know those details. Let me apologize for any inconvenience, but in order to get the most accurate details about the RAID configuration, you will need to get in contact with Dell directly since the chipset belongs to a server board and from our side we cannot confirm how that RAID configuration works, that information is provided by Dell. Regards, Alberto R. Intel Customer Support Technician Under Contract to Intel Corporation

[PCohe1]

Is there anyone viewiing the forum besides Alberto that can offer help or suggestions? I already know that calling Dell would be a waste of time. For example, if you know that it is not possible to rebuild a RAID 1 with 2 degraded drives without deleting the contents of both drives, please say so. Or if you have done this successfully on any brand of system, how did you do it? (If it doesn't work on mine, it doesn't work... but at least we can try it.)

[Alberto_R_Intel]

Hi PCohe1, I also encourage all the peers viewing this thread that if they have any further suggestions or feedback for this scenario to post all the details and comments in this thread. Regards, Alberto R. Intel Customer Support Technician Under Contract to Intel Corporation

[FDeer]

I was at a loss for words when faced with such a similar issue. At the time I actually figured that all my data would be lost whilst I rebuild my RAID. I had a look in to the web for maybe some option to not lose my data and there is a quite helpful place! On my search I tried to do what was told here: https://www.diskinternals.com/raid-recovery/how-to-rebuild-raid-5-without-losing-your-data/. Not always you can recover data, just keep that in mind. But it did in fact help me out, just have to make sure that your files can be recovered. Try not to make the same mistakes I did, All you have to do to avoid RAID 5 death is replace the failed disk itself.

[PCohe1]

Here is the resolution to the problem:

To recap, attempting an invalid 3 drive configuration led to the controller reporting both RAID 1 drives as degraded and no button or any other way to launch a rebuild. The system ran and appeared to have no data loss, but the controller was reporting both drives as degraded.

I installed two different drives and created a RAID 1 set, which worked normally. I then re-installed the two original drives. After booting the system, Windows ran CHKDSK and the RAID controller began to rebuild the drives, which ultimately rebuilt successfully.

I can only speculate about why, but I suspect that what the invalid configuration had written in the controller's NVRAM was preventing the rebuild. When a new RAID set was created, that data was erased from the controller's memory. When the original drives were reinserted, the controller again changed it's memory configuration, but this time as a valid configuration, so that the rebuild proceeded as expected.