一次重启LINUX后，启动ASM实例时，发生了这个错误：
SQL> startup
ASM instance started
Total System Global Area 130023424 bytes
Fixed Size 2071000 bytes
Variable Size 102786600 bytes
ASM Cache 25165824 bytes
ORA-15032: not all alterations performed
ORA-15063: ASM discovered an insufficient number of disks for diskgroup
"DWDATA"
查看错误信息：
15063, 00000, "ASM discovered an insufficient number of disks for diskgroup \\"%s\\""
// *Cause: ASM was unable to find a sufficient number of disks belonging to the
// diskgroup to continue the operation.
// *Action: Check that the disks in the diskgroup are present and functioning,
// that the owner of the ORACLE binary has read/write permission to
// the disks, and that the ASM_DISKSTRING initialization parameter
// has been set correctly. Verify that ASM discovers the appropriate
// disks by querying V$ASM_DISK from the ASM instance.
可以看到这个错误是由于ASM实例无法装载硬盘组的所有磁盘而引起的，有可能是权限问题。马上想到是否是由于OS重启后