恢复失败，请帮忙看看原因

zhengyujinghua

用netbackup4.5做数据库的异机恢复，但到了dbs7后收到了15号的信号后退出。这样剩下的dbs7 dbs8 dbs9三个没有恢复成功。请问下可能是什么原因

还有chunk device是指什么？
15号的信息内容：-15 Block device required.
An operating-system error code with the meaning shown was unexpectedly returned to the database server. An error might exist in the configuration of the database software. That error might include an incorrect address in the chunk-device or tape-device parameters that were given to the database server. Look for other operating-system error messages that might give more information.