Getting the same issues on lInux. I use Vortexbox as my disto and after about a day the RAM has been consumed by Roon.
Core is running on a Intel Core i3 4160 – 3.6GHz, 120GB SSD, 4GB Corsair 1600MHz CL9.
OS is Vortexbox 2.4 which is based on Fedora 23 I believe al up to date. LMS is disabled.
My library is located on my QNAP NAS.
I know my memory is not ideal but I dont really have much running on the machine other than what the OS needs and Roon. I have just setup a Cron job to clear out my memory and cache overnight as an interim measure. I do plan to upgrade my RAM to 8GB at the end of the month.
I updated to the latest build and it seems to have improved I also reduced the memory available to artwork as it had defaulted to 512mb. All seems normal at the moment so you can close this ticket.