Methods are presented for caching I/O data in a solid state drive (SSD) locally attached to a host computer supporting the running of a virtual machine (VM). Portions of the SSD are allocated as cache storage for VMs running on the host computer. A mapping relationship is maintained between unique identifiers for VMs running on the host computer and one or more process identifiers (PIDs) associated with processes running in the host computer that correspond to each of the VM's execution on the host computer. When an I/O request is received, a PID associated with I/O request is determined and a unique identifier for the VM is extracted from the mapping relationship based on the determined PID. A portion of the SSD corresponding to the unique identifier of the VM that is used as a cache for the VM can then be accessed in order to handle the I/O request.