I was rebuilding my unraid system into a new case and didn't pay enough attention to which modular power supply cables I plugged my drives into. Now two data drives and the only parity drive in my 6 drive array won't show up at all. After the drives didn't show up in unraid I immediately powered down and realized my mistake. I've tried the drives with the right sata power power cables and with multiple sata data cables connected to my hba and the motherboard sata ports with none of the drives showing up in unraid. I'm assuming they are completely dead, but if anybody has tips for saving the drive or data that isn't just going to a data recovery service.  All my really important data is backed up to my brother's server, or I would be really freaking out right now. 

 

My primary concern is preserving data on the two data drives and the cache drive, I have a new drive on order to serve as a new parity. What's the best practice for removing the bad drives? 

nas-diagnostics-20190109-1753.zip

21 minutes ago, Wallie37 said:

What's the best practice for removing the bad drives? 

Tools -> New config.

 

As for the dead drives best bet is likely using a service like donor drives or similar.

Haven't looked at diagnostics yet but you're certainly not the first to plug drives in with the wrong modular PSU cables. Several examples on this forum. I believe donordrives is often mentioned in this context. Some people have had luck with swapping out the interface board on the drives to get at the data on the platters.

 

That said, it is very easy to create a new array with just your good drives and their data intact. One way is to just start with a new install since it won't remember anything about your drive assignments. The other way is to go to Tools - New Config and you can change any drive assignments you want. It will just take the disks as they are when you do it either of these ways.

 

There are only a few scenarios where you have to worry about losing data when assigning Unraid disks to the array.

• You assign a data disk to the parity slot. Any data assigned to parity will be overwritten with parity
• You ADD a disk to a new slot in an array that already has valid parity. Any data on a disk in a new slot will be cleared (zeroed) so parity is maintained.
• You assign a disk in place of another disk. Any data on the replacement disk will be overwritten to rebuild the replaced disk.
• You have a disk that won't mount for some reason (filesystem corruption) and Unraid offers to format it. DON'T agree to let it. We can try to repair the filesystem instead.

Don't try to assign any disk to the array that was not an Unraid disk. I'm not entirely sure but I think Unraid might alter its partition if you did that.