Replace parity and several data drives at the same time with no spare sata ports

[DTFagus]

Hey folks, 

 

I may be overcomplicating things in my head right now. Just super scared to make a mistake and lose data. 

Hope you could give me (a beginner friendly) overview of what I need to do. I have read a lot of different posts and tutorials around this issue and some of them are contradictory. 

 

Current scenario: 

• 4TB parity
• 4 TB data
• 4 TB data
• 4 TB data 
• 1 TB data
• 3 TB data 

 

(cache ssds are using the rest of my sata ports) 

 

What I want to do: 

• Change current parity with new 16TB parity
• Remove 1 TB and 3 TB drives and replace with new 16 TB drive 
• Add previous 4 TB parity as data drive 

 

So future desired scenario:

• parity: New 16 TB drive 
• Data: 4 TB
• Data: 4 TB
• Data : 4 TB
• Data: 4 TB (old parity) 
• Data: New 16 TB drive 
• 1 TB and 3 TB data disks removed.

 

I can't add the new 16 TB drives beforehand because I don't have enough sata ports available. 

 

I already used unbalance to empty the 1TB and the 3 TB drives and set all shares to exclude those drives. 

 

Since the number of slots are staying the same I was hoping to do just this: 

1. Power down server
2. Remove 1 TB and 3 TB drives and put in 16 TB drives to those sata ports 
3. Start server
4. Assign all drives as I want to have in the future
5. Start the array and let unraid work its magic (rebuild the parity) 

 

Does that work? 

Or do I need to do something more complicated? 

 

Thanks in advance for your support! 

 

 

[trurl]

Sounds like you've got it.

 

If the drives you are removing are empty, New Config with all disks assigned as you wish and rebuild parity. Be sure you don't assign any data disk to any parity slot. After array starts you can format the new disks including reused parity.

[DTFagus]

Thanks for the quick response! Also asked on reddit and got the answer I need to do one disk at a time with a new rebuilt everytime (making this a week long project): 

So this is not necessarily true? 

So again (sorry for need so much hand holding...): 

1. Power down 
2. Remove drives I dont want anymore and attach new drives 
3. power on
4. Create new config 
5. assign disks as wished (old parity as data drive, new parity drive and new data drive)
6. Start array, let unraid format disks and built parity 

 

Is that right? 

will this mess up anything with my other configs, shares, dockers and the data on the disks? (really worried about pressing that "new config" button... ^^ )

Edited February 16, 2023 by DTFagus

[trurl]

You would have to New Config/Rebuild parity anyway since in the end a disk needs to be removed.

 

[DTFagus]

What do you mean "disk removed"? 
Purely in terms of numbers I am starting both with 1 parity and 5 data drives and ending with 1 parity and 5 data drives. 

[JonathanM]

Technically either method is ok, since you are keeping the same number of drives.

 

However... since you already went through the trouble of emptying two of the drives, there is no need to rebuild them from parity, so the only concern I see is if one of the 3 4TB data drives decided it was time to die.

 

Just remember to rejigger your drive exclusions after everything is in and formatted.

 

Also, the format command is all inclusive, so make sure before you press the button that ONLY the empty drives are listed as unmountable.

 

A clean format is probably better than rebuilding the empty filesystem from the old drives anyway. Yes, there is a significant difference.

 

The only question I have is, are you absolutely positive all the drives except the 1 and 3TB to be removed are in perfect shape?

 

[DTFagus]

At least they are all brand new wd red pro and have been running smoothly the past 2 weeks. Also the real critical stuff is backed up remotely. So in case of a complete failure in this process I lose my movie data (the monitored lists are on mdblist.com anyway) and 2 weeks of work that that went into understanding and setting up unraid (which hopefully can be recovered as well. Settings should be on usb stick (backed up to unraid) and dockerdata is backed up to Google drive). 
 

So I think I do the fast process with just powering down and swapping all necessary drives in one pass and then start the array with the new configuration. 
fingers crossed 🤞 

[DTFagus]

Quote

However... since you already went through the trouble of emptying two of the drives, there is no need to rebuild them from parity, so the only concern I see is if one of the 3 4TB data drives decided it was time to die.

So this would favor using the existing config or creating a new? 

[JonathanM]

6 hours ago, DTFagus said:

So this would favor using the existing config or creating a new? 

New config removes the ability to recover a failed drive until parity has been successfully rebuilt.

[DTFagus]

Just did the update/upgrade. OF COURSE one of the new 16 TB disks was DOA.... So for now I just replaced my 4 TB parity with the working 16 TB drive. also replaced the 1 TB and 3 TB with that 4 TB old parity. Used the "new config" method and worked like a charm building parity now...