[Solved] Parity drive swap help

[ResidentG33k]

I currently have my drives setup as the following:

 

(1) 3TB Parity drive

 

(4) 3TB data drives

 

(1) 120GB SSD cache drive

 

I am looking at replacing my parity drive with an 8TB WD red. I read some articles on this forum and I guess I'm a little confused on what to do. I understood that I need to do a parity check, clear the NEW 8TB parity drive, but what I am uncertain of if I can just put in the 8TB as a secondary parity drive and run a parity check and then take down the original parity drive once the check is good. Sorry for the ramble, I am relatively new to unraid setup. At the moment I haven't plugged in the 8TB drive yet. I am on Unraid 6.3.5. I only want to run one parity drive at the moment until I can afford to buy more larger drives.

 

[itimpi]

Easiest thing to do is to simply change the existing 3TB parity drive to the new 8TB one and let unRAID build new parity on the 8TB drive.    Although technically you are unprotected until this new parity build finishes if you have not added/changed any files on the array while the parity builds then you can always revert to the previous configuration with the old 3TB parity drive.    Once you successfully have the 8TB parity up and working then you can use the old 3TB parity drive as an additional array data drive (assuming you want to do this).

 

Strictly speaking preclearing the 8TB drive is not necessary as its entire contents are overwritten as part of the parity build process.   However many unRAID users like to do the preclear anyway as a way of carrying out an early confidence check on a new drive.  It is your decision as to whether you want to invest time in this additional step.   Pre-clearing the old 3TB parity drive before adding it to the array as an additional data drive makes more sense, but even here (as the drive is presumably in a known ‘good’ state) you may elect to let unRAID clear it as part of adding it as a data drive as this is quicker than the pre-clear (although it still takes some hours).

[ResidentG33k]

Quote

 

1) Shutdown server

2) Install 8TB drive

3) Start server

4) Pre-clear 8TB drive

 

When preclear is finished:

 

5) Assign new 8TB drive to parity slot

6) Unassign old parity drive

7) Shutdown server

8 - Remove old parity drive

9) Start server

10) Wait for parity to rebuild/verify

 

 

 

Does this sound about the right instructions on how to do that? Found another parity upgrade post. Just wanna make sure I do it right and not get anything deleted (although I do have a backup)

Edited January 3, 2018 by ResidentG33k
*edited to reflect correct info

[itimpi]

29 minutes ago, ResidentG33k said:

 

Does this sound about the right instructions on how to do that? Found another parity upgrade post. Just wanna make sure I do it right and not get anything deleted (although I do have a backup)

If following the procedure you outline you would want to reverse steps 5 and 6 as you want the new 8TB drive to end up in the Parity1 slot.

 

I personally would go for a slight faster approach which is:

1. Shutdown server
2. Remove old 3TB parity drive
3. Install 8TB drive
4. Start server
5. Stop array (if auto-started)
6. Assign new 8TB drive to parity1 slot
7. Start array 
8. Wait for parity to rebuild.   This will take some time as although the largest data drive is 3TB, unRAID will still go through building 8TB of parity information. 
9. (optional) Do a parity check to verify the parity build was successful. 

This is on the basis that step 7 completing successfully is a good confidence check on the 8TB drive thus removing the reason for a pre-clear on it.

[ResidentG33k]

Awesome. Thank you. I think this helps me a lot. 

[ResidentG33k]

Marking this as solved.