531.When starting up your ASM instance, you receive the following error:
ASM实例启动时，您会收到以下错误：
SQL> startup pfile=?/dbs/init+ASM.ora
ASM instance started+
Total System Global Area 104611840 bytes
Fixed Size 1298220 bytes
Variable Size 78147796 bytes
ASM Cache 25165824 bytes
ORA-15032: not all alterations performed
ORA-15063: ASM discovered an insufficient number of disks for disk group“DGROUP3”
ORA-15063: ASM discovered an insufficient number of disks for disk group“DGROUP2”
ORA-15063: ASM discovered an insufficient number of disks for disk group“DGROUP1”
In trying to determine the cause of the problem, you issue this query:
SQL> show parameter asm
NAME TYPE VALUE
------------------------------------ ----------- -------------------------
_ asm_allow_only_raw_disks boolean FALSE
asm_diskgroups string DGROUP1, DGROUP2, DGROUP3
asm_diskstring string
asm_power_limit integer 1
asm_preferred_read_failure_groups string
What is the cause of the error? 错误的原因是什么？
A. The ASM_DISKGROUPS parameter is configured for three disk groups: DGROUP1, DGROUP2, and DGROUP3. The underlying disks for these disk groups have apparently been lost.
B. The format of the ASM_DISKGROUPS parameter is incorrect. It should reference the disk group numbers, not the names of the disk groups
C. The ASM_POWER_LIMIT parameter is incorrectly set to 1. It should be set to the number of disk groups being attached to the ASM instance.
D. The ASM_DISKSTRING parameter is not set; therefore disk discovery is not possible.
E. There is insufficient information to solve this problem.
Answer: D

D、ASM磁盘串参数没有设置，因此磁盘是不可能被发现的。

 

ASM_DISKSTRING是一个与操作系统相关的值，ASM使用它来限制搜索时考虑的磁盘集即是设置ASM启动时检查的磁盘，该选项可以同时指定多个值，并且支持通配符。比如只检查/DEV/SD*。默认值为空字符串，为空的话，表示ASM将查找系统中所有ASM拥有读写权限的设备。这在大多数情况下就足够了。如上所示的约束性更强的值可以减少ASM执行搜索所需的时间，从而提高磁盘组装载次数。