I/O故障

ALLSTARS_ORACLE

大家帮忙看看以下问题：环境：Oracle 10.2 RAC on Linux，ASM

刚开始rman备份报错：
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of backup command on ch1 channel at xx/xx/2017 07:01:57
ORA-19501: read error on file "+ORADATA/xxx", blockno xxxxx (blocksize=8192)
ORA-27061: waiting for async I/Os failed


我根据数据块号找到对应的表，然后exp导出也报错：
EXP-00056: ORACLE error 1115 encountered
ORA-01115: IO error reading block from file xx (block # xxxx)
ORA-01110: data file xx: '+ORADATA/xxxx'
ORA-27061: waiting for async I/Os failed
Export terminated successfully with warnings.


然后查看系统日志/var/log/message，有如下报错：
kernel: sd 4:0:0:8: Unhandled sense code
kernel: sd 4:0:0:8: SCSI error: return code = 0x08100002
kernel: Result: hostbyte=invalid driverbyte=DRIVER_SENSE,SUGGEST_OK
kernel: sdad: Current: sense key: Medium Error
kernel:     Add. Sense: Unrecovered read error


次报错就是在执行exp导出时报的。
然后dmesg|grep error查看，也发现报错：
sd 4:0:0:8: SCSI error: return code = 0x08100002
    Add. Sense: Unrecovered read error


通过 sd 4:0:0:8 可以定位到这是ASM磁盘组的一块磁盘。


目前数据库还在正常跑，也还没发现其他故障。