(I am sure I saw the answer to this but I can't find it, so apologies if this is answered already)
I have a pool with 4x2TB spinning disks and 2x1TB SSDs, with about 3TB free. The pool is only for large (legal!) media files and is now pretty much read-only. Should there be any new writes I would like them to land on the SSDs first but I _don't_ want the SSDs to be completely evacuated. Instead, I want to keep a certain % of the SSDs free, but the rest of the space should be considered fine for long term file storage.
Using the SSD plugin gives me the "write first to SSD" but it then tries to completely clear the SSDs.
To put it another way, I want all disks used for file storage, but I want to keep X% of the SSDs free as a write cache.
Is this possible ATM?