Abstract: Systems and methods are discussed relating to allocation of memory from a fixed pool of fast memory within a data center having a data storage area equipped with that memory. Techniques include: receiving a request to write data in the storage area; identifying a file group associated with the write request; analyzing previous data activity traces associated with the file group; determining an available fast memory amount based on the total amount of fast memory in the fixed pool and a currently allocated amount of fast memory; determining a fast memory allocation for the file group based on the previous data activity traces, the available fast memory, and a fast memory constraint, the memory allocation including an allocation amount and a write probability; and providing information about the memory allocation to a file system of the data center, which writes the data based on the allocation amount and write probability.