A write-absorbing, volatile memory buffer for use with a processor module and a non-volatile memory is disclosed. The write-absorbing buffer operates as a dirty cache that can be used to look up both read and write requests, although allocating new blocks only for write requests and not read requests. The blocks are small sized, and a write-only least-recently used cache replacement policy is used to transfer data in the blocks to the non-volatile memory. The write-absorbing buffer can be used to store copy-on-write pages for at least one virtual machine associated with the processor module and reduce write overhead to the non-volatile memory.