备份数据库时出现错误

admwwd

以前用磁带备份数据库一直正常，最近出现错误，错误如下，请各位高手指点，很急，谢谢！
Oct 30 07:54:34 2006: Backup Server: 6.58.1.1: Device '/dev/rmt0.1' supports multiple dump files per volume set.
Oct 30 07:54:35 2006: Backup Server: 6.53.1.1: OPERATOR: Volume on device '/dev/rmt0.1' cannot be opened for write access. Mount another volume.
Oct 30 07:54:35 2006: Backup Server: 6.78.1.1: EXECUTE sp_volchanged
        @session_id = 106,
        @devname = '/dev/rmt0.1',
        @action = { 'PROCEED' | 'RETRY' | 'ABORT' },
        @vname = <new_volume_name>

admwwd

Oct 31 15:47:47 2006: Backup Server: 6.58.1.1: Device '/dev/rmt0.1' supports multiple dump files per volume set.
Oct 31 15:49:16 2006: Backup Server: 6.95.1.13: Error encountered while trying to find the append point on device '/dev/rmt0.1' using non-rewinding tape logic. The tape will be rewound.
Oct 31 15:49:16 2006: Backup Server: 4.141.2.41: [11] The 'ioctl' call failed for device '/dev/rmt0.1' with error number 9 (Bad file number). Refer to your operating system documentation for further details.
Oct 31 15:49:16 2006: Backup Server: 1.14.2.2: Unrecoverable I/O or volume error.  This DUMP or LOAD session must exit.
Oct 31 15:49:16 2006: Backup Server: 6.45.1.1: Be sure to remove the tape/floppy from drive /dev/rmt0.1 (server: , session id: 145).