A storage system, including: one or more mass storage devices, coupled to store data at respective first ranges of logical addresses (LAs), and one or more interfaces, which are adapted to receive input/output (IO) requests from host processors directed to specified LAs. The system also includes a plurality of caches coupled to the one or more interfaces so as to receive the IO requests therefrom, each cache being assigned a respective second range of the LAs and being coupled to the one or more mass storage devices, the respective first ranges of which overlap the respective second range, so as to receive data from and provide data to the one or more mass storage devices, and being coupled to accept the IO requests within the respective second range directed thereto.