Shrink array help needed. Removing an unwanted drive Please help

[alitech]

I have a very loud seagate desktop drive in the array. This is so loud that it causes the whole system to vibrate and also makes a humming noise when idle that i can hear in the next room. It is also the parity drive unfortunately. 

Anyhoo, I have a drive within the array that I would like to replace it with. It is a WD red and will do the trick. 

 

If you see my configuration, I want to replace Parity Drive with Disk 3. Image attached.

 

I have seen instructions on how to do this on the wiki here:  https://wiki.unraid.net/Shrink_array

 

I am going to be using the first method. As I have 2 parity drives, I don't think I want to risk doing method 2. 

 

I think the instructions are slightly flawed or incomplete. Here is what they look like from the wiki

 

Quote

 

The "Remove Drives Then Rebuild Parity" Method

For removing one or more drives from an unRAID array - this is the tried and true method

Note: this section has been tested for 6.2, but is still fairly new

This method does not keep the drive's data within the array. If the drive to be removed has data you want to stay in the array, you must move it yourself to the other data drives. Parity will be built based entirely and only on the remaining drives and their contents.

This method is best if you are removing more than one drive.

This method should be used if you need to preserve the contents of the data drive you are removing from the array.

This method MUST be used if the drive cannot be cleared, that is, it is missing, disabled, or has bad sectors.

This method does NOT preserve parity, so parity will have to be rebuilt once the array assignments have been adjusted.

Procedure

Make sure that the drive or drives you are removing have been removed from any inclusions or exclusions for all shares, including in the global share settings. Shares should be changed from the default of "All" to "Include". This include list should contain only the drives that will be retained.

Make sure you have a copy of your array assignments, especially the parity drive. You may need this list if the "Retain current configuration" option doesn't work correctly

Stop the array (if it is started)

Go to Tools then New Config

Click on the Retain current configuration box (says None at first), click on the box for All, then click on close

Click on the box for Yes I want to do this, then click Apply then Done

Return to the Main page, and check all assignments. If any are missing, correct them. Unassign the drive(s) you are removing. Double check all of the assignments, especially the parity drive(s)!

Do not click the check box for Parity is already valid; make sure it is NOT checked; parity is not valid now and won't be until the parity build completes

Start the array to commit the changes; system is usable now, but it will take a long time rebuilding parity

 

 

• I have used unbalance to move the data to other disks on the array, so that part is done. 
• I have checked the shares settings and ensured that Disk 3 is not being used for anything else
• Snapshot of array assignments captured and attached.

 

Now comes the tricky part that is not mentioned in the instructions. Stopping the array and doing a new config. 

 

The instructions dont tell you what to do if I want to change the parity drive itself

 

It also fails to mention what to do when drive assignments if one of the disks are removed. Shouldn't the new configuration be configured in a way where each disk number changes as one of the drives is being removed? As I am removing Disk 3 from the array and making that into a parity disk:

 

Disk 4 should become Disk 3

Disk 5 should become Disk 4

Disk 6 should become Disk 5

Disk 7 should become Disk 6

 

Am I right or have I got this wrong?

 

 

Edited March 10, 2021 by alitech

[itimpi]

Changing drive assignments after a New Config is exactly the same process for both data and parity drives.    You can change them to be different drives or leave the entry unassigned.
 

it is perfectly permissible to have gaps in the data drive assignments so whether you move them up because you prefer it that way or leave a gap is up to you.

 

the important point is to make sure that any drive assigned to a parity slot does not contain contents you want to keep as when you start the array to build new parity (based on the drive assignments at that point) any data on the parity drives would be lost as it is over-written with parity information.