SSDs do not have the same usage settings.

[phhowe17]

I have two SSDs in my system which are both marked as SSD not archive drives.  Re-balancing empties one, but not the other. The one that empties in an actual SATA SSD, the other is a NVME drive.  Running DrivePool v2.3.1.3.1687

I have the following balancers active

- Disk Space Equalizer: Equalize by free space remaining, File Types - both checked.

- SSD Optimizer: All drives are Archive except the two SSD/NVME drives

- StableBit Scanner: Move un-duplicated files out of damaged drives, move duplicated files out of damaged drive, Never allow placement on evacuated drives.

- Volume Equalization: enabled

- Drive Usage Limiter:  All drives allow dup and undup file placement

- Prevent Drive Overfill: Try not to filll above 80%, or 100 GB free, Empty the drive up to 85% or 200 GB free

- Duplication Space Optimizer: Enabled (duplication not enabled)

- Ordered file placement: disabled.

Only one pool in the system, with 12 drives totaling 137 TB

[phhowe17]

I'd never changed the default order of the balancers. Bumping the SSD balancer to the top seems to have fixed it.

 

I do not have any file placement rules in place.

[Shane]

What is the priority order of your balancers? E.g. normally StableBit Scanner should be at the top if enabled, and normally I would suggest SSD Optimizer should be next. 

You mention "Duplication Space Optimizer: Enabled (duplication not enabled)" but the targets in the pictures are suggesting duplication is enabled?

Are you using any File Placement rules that point at the SSDs?