I'm currently running version 6.12.13 and I've reached the point where I'm going to retire some older 4xHGST 4TB drives that I have in my system. Ultimately I want to replace the existing dual 12TB parity drives with a single 20TB parity drive. Then transfer the existing 12TB parity drives be be data drives. I'm having a difficult time wrapping my head around the sequence of doing this and making sure I'm not going to run into issues.

 

My initial plan to minimize the number of parity rebuilds is:

 

1) Reconfigure the drives, unassign Parity 1 & 2 and assigning the new 20TB drive to be parity 1.

2) Let parity rebuild occur while I keep my old parity drives off to the side in the event that something may happen.

3) Once parity sync occurs I'll format and add my old 12TB drives to the array. (No sync is required when adding drives, right?)

4) Use Unbalance to move data off one HGST 4TB drive at a time to the new 12TB data drives.

5) Follow The "Clear Drive Then Remove Drive" Method to remove each drive thats been emptied.

6) Repeat steps 4 and 5 x3 to remove the remaining drives.

 

Is this correct?

 

I'm having doubts this is the correct approach and I'd hate to lose everything.  I'd appreciate it if others could chime in and give me a bit of guidance.

For #3, you'd need to pre-clear them which writes all 0s to the disks in order to keep parity sync'd, format alone won't prevent parity sync. 

 

You've got enough space to unbalance the drives now. So you could:

unbalance the 4 4TB drives while you have dual parity. 

Add the single parity, and sync and verify. 

pre-clear the 2 12TB drives outside of the array.

Add the pre-clear'd disk into the array without parity sync.

You can split the last 2 steps into 2:

Add the 20TB as parity1, then pre-clear the old parity 1 and then add it back into the array while it still has dual parity. 

Remove dual parity only when you run out of data space or get another 20TB and then add the 12TB as data while keeping dual parity. 

 

Another approach would be to add the 20TB as parity 1 and then replace any of the 4TB with the 12TB(rebuild the 4TB onto the 12TB) and rise and repeat gradually as you need more space. 

 

 

Edited December 2, 20241 yr by foo_fighter

Awesome! Thank you so much for the response and alternative suggestions. I would of never considered those options beforehand. However at this point I'm looking to slim down the server to a minimum by removing the 4TB drives. They're power on hours have reached 8 years and its only a matter of time until they give out on me and I'm having to work on it again.

 

Based on reading your post and based on what I know the proper steps include:

 

1) Change all my shares inclusion settings to write new data only to disk 5 & 6.

2) unbalance all 4x4TB drives (disk 1-4)

3) Initiate new configuration and unassign Parity 1 & 2 and assigning the new 20TB drive to be parity 1.

4) Let parity rebuild occur while I keep my old parity drives off to the side.

5) Parity rebuild completes and I Preclear the old 12TB parity drives in unassigned devices and then add them to array when ready.

5) Follow The "Clear Drive Then Remove Drive" Method to remove one 4TB drive at a time.

6) Repeat step 5 3-more additional times until the 4TB disks are removed.

 

Sound about right? My wife and kids would kill me if I lose the media on there and I'm in too deep to start over again. 😟

Thanks again!

 

 

The last steps are redundant if you're rebuilding parity anyway.

 

1) Change all my shares inclusion settings to write new data only to disk 5 & 6.

2) unbalance all 4x4TB drives (disk 1-4) 

I would modify step 2 slightly to not move, but copy the data so you have a backup

 

3) Initiate new configuration and unassign Parity 1 & 2 and assigning the new 20TB drive to be parity 1 and remove 4 X 4TB drives.

4) Let parity rebuild occur while I keep my old parity drives and 4 X 4TB drives off to the side.

5) Parity rebuild completes and I Preclear the old 12TB parity drives in unassigned devices and then add them to array when ready.

Triple check all data before pre clearing the old 12TB, since this is the last time you can go back to the previous config.

 

Let us know how it goes. 

 

On 12/2/2024 at 9:45 PM, foo_fighter said:

The last steps are redundant if you're rebuilding parity anyway.

 

1) Change all my shares inclusion settings to write new data only to disk 5 & 6.

2) unbalance all 4x4TB drives (disk 1-4) 

I would modify step 2 slightly to not move, but copy the data so you have a backup

 

3) Initiate new configuration and unassign Parity 1 & 2 and assigning the new 20TB drive to be parity 1 and remove 4 X 4TB drives.

4) Let parity rebuild occur while I keep my old parity drives and 4 X 4TB drives off to the side.

5) Parity rebuild completes and I Preclear the old 12TB parity drives in unassigned devices and then add them to array when ready.

Triple check all data before pre clearing the old 12TB, since this is the last time you can go back to the previous config.

 

Let us know how it goes. 

 

This is working perfectly so far. I'm rebuilding parity right now but all my data is copied over on the drives I'm retaining. I honestly don't know why I was thinking this whole process was super complicated. Thank you so much for the help!

Edited December 6, 20241 yr by osker246
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