公司的服务器数据库是用networeker 的 legato 备份软件备份的。其中的一台数据库同事在配置networker的时候配置磁带设备配置成st0。然后造成不能恢复数据库。

值得庆幸的是这个数据库里面的资料比较少。

当时因为阵列柜问题重新创建阵列，在创建阵列以前用磁带备份了一下，最后竟然是不能恢复。郁闷。可见备份也是一定要备份好才可以。

informix 数据库 onbar -r 恢复的时候报：
01:03:24 IBM Informix Dynamic Server Started.

Wed Nov 7 01:03:25 2007

01:03:25 Buffer manager: env variable NOFUZZYCKPT is
defined. All checkpoints will be hard checkpoints.
01:03:25 Event alarms enabled. ALARMPROG = '/home/informix/etc/alarmprogram.sh'
01:03:25 Booting Language from module <>
01:03:25 Loading Module
01:03:25 Booting Language from module <>
01:03:25 Loading Module
01:03:30 DR: DRAUTO is 0 (Off)
01:03:30 IBM Informix Dynamic Server Version 10.00.UC4 Software Serial Number AAA#B000000
01:03:30 Cannot Open Primary Chunk '/informix.links/database/rootdbs', errno = 6
01:03:30 IBM Informix Dynamic Server Stopped.

01:03:31 mt_shm_remove: WARNING: may not have removed all/correct segments
[informix@tonykorn97 informix]$

nsr log 中报:
11/07/07 02:28:54 nsrd: /dev/st0 mount operation in progress
11/07/07 02:30:09 nsrd: media info event: 4mm tape tonykorn97.05 will be needed
11/07/07 02:23:13 nsrd: media event cleared: confirmed mount of tonykorn97.05 on /dev/st0
11/07/07 02:23:13 nsrd: tonykorn97:INFORMIX:/ontonykorn97/rootdbs/0 (11/06/07) starting read from tonykorn97.05 of 6.8 MB
11/07/07 02:23:14 nsrd: media info: can not read record 0 of file 2 on 4mm tape tonykorn97.05
11/07/07 02:23:14 nsrd: tonykorn97:INFORMIX:/ontonykorn97/rootdbs/0 (11/06/07) done reading

发现当时的networker中设置磁带为st0,scanner的时候错误
scanner: SYSTEM error, tape label read, Input/output error
scanner: scanning for valid records...
scanner: read: -1 bytes : Input/output error
scanner: Cannot continue
scanner: No valid tape records found