Techniques herein are for chaining nonvolatile storage devices to achieve high availability. A method involves a storage server receiving a write request to store data blocks in a first nonvolatile memory device. The storage server comprises a plurality of nonvolatile memory devices that cache data blocks stored on primary storage. The plurality of nonvolatile memory devices comprises the first nonvolatile memory device. The storage server maintains a cache index of data blocks that reside in the plurality of nonvolatile memory devices. Based on one or more criteria, the storage server reroutes the write request to a second nonvolatile memory device of the plurality of nonvolatile memory devices and stores an identifier of the second nonvolatile memory device in the cache index.