Reorganizing my pools

[TomTiddler]

I currently have two pools, and last week due to an issue with my hardware, I needed to rearrange a lot of data (>20TB). As of this message I have all of my data on one pool, unduplicated. I'd like to make the second pool (currently empty) act as the "duplicated store", so that all the primary data is on Pool 1, and all of the duplicated data (and only duplicates) is on Pool 2. I know I can make Pool 2 a member of Pool 1, but I can't figure out what the file placement settings should be to make all the duplicates be on Pool2 and all the originals on Pool1. 

In effect I want Pool 2 to be a mirror of Pool 1.

Is there a simple solution that I'm missing?

[Jonibhoni]

DrivePool doesn't have the concept of a "primary" and a "secondary" pool. So there is no "only duplicates" in the meaning of "the copy of the original" because there is no "original" - all two copies of a 2x-duplicated file are valid and equal. DrivePool fetches any of them when you access it and just makes sure that there are always 2x the file stored physically within your pool, without any of them being superior.

So much for the theory. In practice, what you want to do ...

1 hour ago, TomTiddler said:

I want Pool 2 to be a mirror of Pool 1.

... is perfectly doable. You create a third, "parent" pool that contains pool 1 and pool 2 (and nothing else). In this parent pool, you set duplication for the whole pool to 2x. (In the lower pools 1 and 2, you disable duplication). Then you move all your files to the parent pool and DrivePool will distribute one copy of each file on pool 1 and one copy on pool 2.

If you simply move the files from your original pool (now "pool 1") to the parent pool, you will be fine, you just have to wait for all the 20 TB being moved. If you are more adventurous, you can also go through a procedure referred to as "seeding" (https://wiki.covecube.com/StableBit_DrivePool_Q4142489) which will skip half of the disk writing work (but is more difficult and risky).

[TomTiddler]

3 hours ago, Jonibhoni said:

DrivePool doesn't have the concept of a "primary" and a "secondary" pool. So there is no "only duplicates" in the meaning of "the copy of the original" because there is no "original" - all two copies of a 2x-duplicated file are valid and equal. DrivePool fetches any of them when you access it and just makes sure that there are always 2x the file stored physically within your pool, without any of them being superior.

So much for the theory. In practice, what you want to do ...

... is perfectly doable. You create a third, "parent" pool that contains pool 1 and pool 2 (and nothing else). In this parent pool, you set duplication for the whole pool to 2x. (In the lower pools 1 and 2, you disable duplication). Then you move all your files to the parent pool and DrivePool will distribute one copy of each file on pool 1 and one copy on pool 2.

If you simply move the files from your original pool (now "pool 1") to the parent pool, you will be fine, you just have to wait for all the 20 TB being moved. If you are more adventurous, you can also go through a procedure referred to as "seeding" (https://wiki.covecube.com/StableBit_DrivePool_Q4142489) which will skip half of the disk writing work (but is more difficult and risky).

Many thanx @Jonibhoni, i had come to much the same conclusion, but was hoping to avoid the "seeding" process. Oh well, nothing ventured ........ I guess I'll give it a go tomorrow