May 26 12:27:44 node3 kernel: sr 2:0:0:0: Device not ready: <6>: Current: sense key: Not Ready
May 26 12:27:44 node3 kernel:     Add. Sense: Medium not present - tray open
May 26 12:27:44 node3 kernel:
May 26 12:27:44 node3 kernel: end_request: I/O error, dev sr0, sector 64
May 26 12:27:44 node3 kernel: Buffer I/O error on device sr0, logical block 8
May 26 12:27:44 node3 kernel: sr 2:0:0:0: Device not ready: <6>: Current: sense key: Not Ready
May 26 12:27:44 node3 kernel:     Add. Sense: Medium not present - tray open
May 26 12:27:44 node3 kernel:
May 26 12:27:44 node3 kernel: end_request: I/O error, dev sr0, sector 64
May 26 12:27:44 node3 kernel: Buffer I/O error on device sr0, logical block 8

CDROM 에 의해 발생 될 수도 있다. cd title 혹은 cdrom 문제 로 인해..