I want to add second parity drive

[wdelarme]

I'd like to add a second parity drive on a 5 disk array that has only one parity. What would be the best way to move these drives around without losing info on the array I have now?

 

As it is now I have

 

Drive 1 Parity 3TB

Drive 2 Array 3TB

Drive 3 Array 3 TB

Drive 4 Array 3TB

Drive 5 Array 3TB

 

I want it to be like this

Drive 1 Parity 3 TB

Drive 2 Parity 3TB

Drive 3 Array 3TB

Drive 4 Array 3 TB

Drive 5 Array 3 TB

 

I have approx. 2 TB of data on the array now

[ashman70]

Just curious why you want to add a second parity drive on such a small array?

[wdelarme]

9 TB is about 4 times as much as I need at my house. This is just personal stuff

[trurl]

45 minutes ago, wdelarme said:

9 TB is about 4 times as much as I need at my house. This is just personal stuff

In order to remove a data drive and reuse it as parity, you will have to shrink the array by moving everything off one of the data drives, setting a New Config with that drive assigned as parity2, and resync both parity drives.

 

Personally, I think with only 2TB of data I would go with a single data, single parity configuration and save the other disks as spares and add them as you need capacity. Less drives in the system means less possibility of problems. Of course, the warranty clock will be ticking whether or not you are using the spare disks.

 

At what point it makes sense to add parity2 is debatable but parity2 does protect in the event of another disk getting disabled while rebuilding a disabled disk. How likely this scenario is depends on how diligent and careful you are.

 

I say diligent because 2 disks are unlikely to really fail at the same time, so if you are diligent and take care of one disk when it begins to have problems, you aren't likely to get another actual disk failure. Do you have Notifications setup?

 

I say careful because by far the most frequent cause of disabled disks is connection issues. Be careful with your cabling and connectors.

 

The main reason I went ahead with parity2 even though I only had 5 data was because I wanted the "experience".

[ashman70]

I agree with Trurl, I think in your case a second parity drive isn't really necessary, the drives in your array are 3TB and the rebuild time for them might be 4-6hrs which isn't significant. I would leave things as they are unless you are really worried about losing two disks at once.

[wdelarme]

I basically just want to do it for experience. If I remove the drive with array offline then set that drive in unraid to "no drive" and start the array will that move the files to another drive? I hope I explained that right. Is moving those files off a manual evolution?

[trurl]

1 hour ago, wdelarme said:

I basically just want to do it for experience. If I remove the drive with array offline then set that drive in unraid to "no drive" and start the array will that move the files to another drive? I hope I explained that right. Is moving those files off a manual evolution?

There is no automatic moving of files except as happens with cache moving.

 

And if you remove a drive and start without it you must set a New Config without it and rebuild parity, or you must replace it and have the drive rebuild.