Just install a RouterOS server, on a HD etc. Run a demo license for 24 hours or if you need it more, install a license (not expensive). Then you will have a CALEA server for the future as well. Also, it has been suggested to allow writing this to a secondary, non system drive.
, CCIE, MCTCE, MTCNA, MCTCTE, MTCWE, MTCNIE, A+, N+, MCP, Mikrotik Certified Consultant / TrainerNeed Mikrotik Support
-- Link Technologies, Inc.--- Author of "Learn RouterOS: Second Edition"