NVF_HDR_VERSION
(hdr.nvfh_ver != NVF_HDR_VERSION) ||
NVF_FILENAME, NVF_HDR_VERSION, NVF_CURR_FILE_SUFFIX);
NVF_FILENAME, NVF_HDR_VERSION, NVF_PREV_FILE_SUFFIX);
((nvf_hdr_t *)nvfbuf)->nvfh_ver = NVF_HDR_VERSION;