asm实例中进行检查:
SQL> alter diskgroup dgtest check;
Diskgroup altered.
这时我们查看asm实例中日志信息:
可以看到红色部分就显示不能读取磁盘头信息，这个时候我们就要介入处理了。
SQL> alter diskgroup dgtest check
Tue Jul 22 17:54:47 2014
ERROR: Could not read the header of disk DGTEST_0000 (0).
NOTE: process _user12084_+asm (12084) initiating offline of disk 0.3914034847 (DGTEST_0000) with mask 0x7e in group 2 (DGTEST) without client assisting
NOTE: initiating PST update: grp 2 (DGTEST), dsk = 0/0xe94b6e9f, mask = 0x6a, op = clear
Tue Jul 22 17:54:47 2014
GMON updating disk modes for group 2 at 24 for pid 23, osid 12084
ERROR: disk 0(DGTEST_0000) in group 2(DGTEST) cannot be offlined because the disk group has external redundancy.
Tue Jul 22 17:54:47 2014
ERROR: too many offline disks in PST (grp 2)
Tue Jul 22 17:54:47 2014
ERROR: Failed to offline disk DGTEST_0000 (0).
NOTE: starting check of diskgroup DGTEST
Tue Jul 22 17:54:48 2014
ASM Health Checker found 1 new failures
Tue Jul 22 17:54:48 2014
ASM Health Checker found 1 new failures
Tue Jul 22 17:54:48 2014
GMON checking disk 0 for group 2 at 25 for pid 23, osid 12084
修改磁盘头后，我们再次做检查
没有任何报错
SQL> alter diskgroup dgtest check
Tue Jul 22 18:07:50 2014
NOTE: starting check of diskgroup DGTEST
Tue Jul 22 18:07:51 2014
GMON checking disk 0 for group 2 at 26 for pid 23, osid 12084
Tue Jul 22 18:07:53 2014
SUCCESS: check of diskgroup DGTEST found no errors
Tue Jul 22 18:07:53 2014
SUCCESS: alter diskgroup dgtest check