1. A system, comprising: a processor and logic integrated with and/or executable by the processor, the logic being configured to cause the processor to: receive indication of failure of a primary cache server that is configured to manage read requests and write requests for a back-end storage device; set a secondary cache server to a by-pass mode for read requests directed to portions of the back-end storage device managed by the primary cache server prior to the failure, the secondary cache server being configured to manage read requests and write requests for the back-end storage device; and read an index of cache block descriptors (CBDs) managed by the primary cache server prior to the failure into a memory of the secondary cache server, wherein a complete metadata footprint of the primary cache server is not read into the memory of the secondary cache server, wherein CBDs indicated by the index of CBDs managed by the primary cache server prior to the failure provide coarse-grained mapping of data on the back-end storage device, wherein a plurality of fine block descriptors (FBDs) are allocated to each of the CBDs indicated by the index of CBDs managed by the primary cache server prior to the failure, and wherein each FBD of the plurality of FBDs provide fine-grained mapping of data stored to a cache storage device.