[SOLVED] 2 data and 2 cache drives failed

[AntonKovalenko]

Hi all, please help with some guidance.

 

I have 4 drives failed at once, 2 data and 2 cache. Drives are a total loss, burnt due to a faulty cable.

2 parity drives and 3 other data drives are fine.

Failed drives were added recently and contained next to no data.

I am prepared to accept the loss of data on the failed drives - but not on the remaining.

Rebuild is preferable of course, if possible.

 

ASK: Please help with the procedure to rebuild (or replace with empty drives) the two failed data drives.

If rebuild/replace is not possible, please explain how to back up the data from the remaining drives - after that I can rebuild the array completely myself.

 

For cache drives I think the replacement procedure would be standard - please advise if not so.

I did cache drives replacement once, it was easy.

 

System version is the latest, 6 something, updated recently, don't want to power up the system to check the exact version now.

 

I'll be buying replacement drives tomorrow.

 

 

Please forgive me for asking for something that may be googled.

Loosing four drives at once made me somewhat uneasy and nervous, I don't trust my judgement now.

Procedure for one failed data drive is easy to find, two is trickier, or so it seems.

 

 

 

 

Edited May 9, 2020 by AntonKovalenko

[JorgeB]

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

-Assign any new data and/or cache drives you want

-Start array to begin parity sync

-New drives added will need to be formatted, unless already valid Unraid devices

[AntonKovalenko]

Success report:

 

IMPORTANT NOTE: I had TWO parity drives intact and TWO data drives that failed

 

I started with -Tools -> New Config -> Retain current configuration: All -> Apply as suggested by johnnie.black above (many thanks for the quick reply)

 

There was a very specific warning message that after this New Config operation no data rebuild is possible - which made me think that a rebuild MAY be possible if I just add new replacement drives instead of the failed ones. I did that, and rebuild of both drives commenced immediately after the array was started. The array even emulated the content of the failed drives while rebuilding, which was working well, albeit slow.

 

To be specific: I added replacement drives instead of old ones on the MAIN tab, with array stopped. Intact drives, including parity, were left as they were. Then I started the array, and the rebuild followed automatically.

 

I added new cache drives afterwards with no issue. No data rebuild for those, but in my case it did not matter.

 

 

Edited May 9, 2020 by AntonKovalenko

[JorgeB]

I'm sorry, I have the bad habit of sometimes reading posts too fast, in this case I read this:

On 5/6/2020 at 4:14 AM, AntonKovalenko said:

Failed drives were added recently and contained next to no data.

as

On 5/6/2020 at 4:14 AM, AntonKovalenko said:

Failed drives were added recently and contained no data.

That's what my suggestion was based on, glad you found the way to rebuild them.