So I've got various shares all set to the High-Water allocation method. My HW setup:

 

HP Microserver N54L

1x Seagate 4TB as Parity Drive (XFS)

2x WD Greens 2TB as Disk 1 & Disk 2 (XFS)

1x Samsung 2TB as Disk 3 (XFS)

1x Sandisk 64GB SSD (btrfs) as cache

1x OCZ 60GB SSD (btfs) as future cache pool (currently unused & unassigned)

 

So currently, i'm using 1.01TB (with 991GB free) on Disk 1. Surely as disk 1 reaches 1000GB free (the halfway point) then any and further data should be written to the next disk (disk 2 in this case) but it hasnt done this. Both disk 2 & disk 3 are empty. Currently running 6.0-beta12

What about your split level settings?

For example, my TV share is set to automatically split only the top two directory levels as required. For reference:

 

TV\Show 1\Season 1,2,3,4etc..\episodes

TV\Show 2\Season 1,2,3,4etc..\episodes

 

Etc..

 

Infact; I've now set this share to Automatically split any directory as required; so this *should* work if splitting was causing the issue.

 

Edit -

 

Just invoked mover and its still writing to Disk 1 (from cache).

If the sub folder already exists, unraid will try to write to the existing folder instead of creating a duplicate one on another disk.

Sounds to me that the split level isn't allowing a duplicate directory to be created on a new disk. Maybe you should give an actual example.

 

Check the global share settings on the settings tab and make sure you didn't exclude disks there.

Fixed it by setting split level to automatically split any directory as required