[Solved] BTRFS 2 drive cache to 1 drive (fastest method)

[daddygrant]

Hey,

 

I'll like to go from my two 480GB SATA SSD cache to a single Intel Enterprise 1.2TB NVMe cache drive.

 

Currently both SATA drives are in a cache pool.  I can have all three drives physically connected to facilitate the move.  So, I need a sanity check on the fastest method to get this down with minimal down time (I do have backups just in case).  Here is what I'm thinking.

 

Method 1

1.  Stop array

2. Set Cache from 2 to 3

3. Assign NVMe to slot 3

4. Start array

5. run a balance (Anything special needed?)

6. Stop array

7. Unassign the two SATA drives from cache setting

8. Start array

 

Method 2 (A friend's suggestion due to BTRFS magic )

1.  Stop Array

2. Remove both SATA from Cache assignment

3. Assign NVMe to slot 1

4. Start Array

 

Thoughts?

 

Edited February 11, 2020 by daddygrant

[JorgeB]

16 hours ago, daddygrant said:

Method 2 (A friend's suggestion due to BTRFS magic )

1.  Stop Array

2. Remove both SATA from Cache assignment

3. Assign NVMe to slot 1

4. Start Array

This won't work, you can replace one of them with the NVMe device and only them remove the other, this can all be done with the pool online, except when stopping/starting the array, instructions for all those procedures are in the FAQ:

 

[daddygrant]

On 2/9/2020 at 3:06 AM, johnnie.black said:

This won't work, you can replace one of them with the NVMe device and only them remove the other, this can all be done with the pool online, except when stopping/starting the array, instructions for all those procedures are in the FAQ:

 

Thanks... I figured it out after re-reading some of your previous posts on the matter.

 

What I did. There is minor down time between stopping the array to assign the drive.

1. Unassign old drive 1 from the pool

2. Let cache balance

3.Assigned the new drive into the pool.

4. Let cache balance

5. Unassign old drive 2 from the pool

6. Let cache balance

8. Drink beer and enjoy my new larger single drive.

 

Edited February 10, 2020 by daddygrant