mount 에러가 발생...?!

mount 디렉토리에 아무 명령어도 안된다?!

내가 겪은 일은 아니지만 같이 일하시는분이 mount 작업을 하시다가 겪은 일을 남겨봄

/var/log/messages OS 로그 

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 1, udp): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 1, tcp): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 1, udp6): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 1, tcp6): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 2, udp): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 2, tcp): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 2, udp6): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 2, tcp6): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 3, udp): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 3, tcp): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 3, udp6): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: Failed to register (mountd, 3, tcp6): svc_reg() err: RPC: Remote system error - Connection refused

Jul 19 15:49:23 localhost rpc.mountd[6469]: mountd: could not create listeners

Jul 19 15:49:23 localhost kernel: svc: failed to register nfsdv2 RPC service (errno 111).

Jul 19 15:49:23 localhost kernel: svc: failed to register nfsaclv2 RPC service (errno 111).

Jul 19 15:49:23 localhost kernel: nfsd: last server has exited, flushing export cache

Jul 19 15:49:23 localhost kernel: svc: failed to register nfsdv2 RPC service (errno 97).

Jul 19 15:49:23 localhost kernel: svc: failed to register nfsaclv2 RPC service (errno 97).

Jul 19 15:49:23 localhost kernel: nfsd: last server has exited, flushing export cache

일단 에러는 이러하였으며 해당 mount 디렉토리의 어떤 명령도 듣지 않았다. 삭제, 이동, mount, umount 등등

고민을 하던 중 어떤분이 해결을 해주셨는데 OS 로그를 참고하여 판단했을때 

단순히 현재 문제가 발생한 mount 디렉토리를 umount를 해주면 되는 것인데 요지는 umount를 어떻게 하느냐가 문제였으나

umount -l 옵션으로 해당 디렉토리를 umount를 할 수 있었다고 하셨다. 

umount -f 옵션만 사용했는데 이번에 새로운 옵션을 알게됐다... 굿...

mount, umount 옵션 참고 - http://devanix.tistory.com/241

* 서버는 centos