unzip 관련 질문요~

압축을 하고 싶어서 unzip 명령어를 입력했더니 오류가 나는데 해결 법 좀  알 수 있을까요?

Archive:  linux.x64_11gR2_database_1of2.zip
  End-of-central-directory signature not found.  Either this file is not
  a zipfile, or it constitutes one disk of a multi-part archive.  In the
  latter case the central directory and zipfile comment will be found on
  the last disk(s) of this archive.
note:  linux.x64_11gR2_database_1of2.zip may be a plain executable, not an archive
unzip:  cannot find zipfile directory in one of linux.x64_11gR2_database_1of2.zip or
        linux.x64_11gR2_database_1of2.zip.zip, and cannot find linux.x64_11gR2_database_1of2.zip.ZIP, period.