Hello,

 

As the title suggests I have a failed disk, (It's not being discovered by the sata controller). This just happened, I know my parity is valid. But my server frooze up, and I had to power down manually, so Unraid isn't trusting the parity. What is the best way to fix this?

 

I am using Unraid 6.0.1

 

Thank You

Not clear from your description. Does the webui show a disk is missing? Maybe post a screenshot.

Hello Trurl,

 

Thanks for helping, here is the screen shot you requested.

 

Thank You

Not sure what you meant about unRAID not trusting parity. Disk9 is disabled. Go to Tools - Diagnostics and post the diagnostics zip file.

Hello Trurl,

 

The disk is disabled because the controller cannot see the drive, as in hardware failure.

 

How do I put in a new disk and rebuild from parity if parity is not considered valid, even though i know it to be?

 

Thank You

I still don't know what you mean about the parity is invalid. The screenshot says "Data is invalid". The disk is disabled, but unRAID should be emulating it and you should be able to read the data on the emulated disk.

 

Please go to Tools - Diagnostics and post the diagnostics zip file.

Hello Trurl,

 

In the past it has been my experience that if an Unraid Server was incorrectly powered down, it would consider parity to be invalid, and want to rebuild it. Am I wrong? The array is emulating the disk, should I just follow the standard failed disk replacement procedure then?

 

Attached are the diagnostics you requested.

 

Thank You

unraid-diagnostics-20150906-2032.zip

unRAID considers the parity data suspect if there has been an unclean shutdown and so it will usually start a correcting parity check, which is not technically the same as rebuilding it. But in this case you have a disabled disk, so you will have to rely on parity and all the other drives to rebuild the data disk.

 

Do you have another disk to rebuild to?

Yes

unRAID only requires a clear disk when you are adding it to a new slot, so parity will remain valid. A clear disk is all zeroes and so has no effect on parity.

 

In this case, you are replacing a disk, so the disk does not have to be clear. However, it is usually recommended that any disk to be used in the array be fully tested using the preclear script or some other method. Every bit of every disk is needed when one of them fails so you want to be able to trust them.

 

Wiki: Replacing a Data Drive

Thank you for your help Trurl!