ORA-15040: diskgroup is incomplete
Cause: Some of the disks comprising a diskgroup were not present.
Action: Check the hardware to ensure that all disks are functional. Also check that the setting of the ASM_DISKSTRING initialization parameter has not changed. Alternatively, for normal or high redundancy diskgroups, use MOUNT FORCE to offline missing disks as part of mounting the diskgroup.
ORA-15040: diskgroup is incomplete
Cause: The diskgroup is only partially mounted or not mounted at all.
Action: Check the alerts log file and system log file to determine the cause of the incomplete diskgroup.
ORA-15040错误一般是由于一个ASM磁盘组未被正确挂载而导致的，一个ASM磁盘组必须都被挂载，只有当所有磁盘都挂载成功了，ASM磁盘组才被完全挂载。
（1）通过SQL：在SQL中查看磁盘组的挂载情况。
SELECT name, state FROM v$asm_diskgroup;
（2）若结果显示DISMOUNTED，则需要重新挂载磁盘组：
ALTER DISKGROUP “DATA_HIG” MOUNT;
（3）若结果显示MOUNTED，则可能是某些磁盘未挂载，需要进一步判断：
SELECT name AS disks_name, mode_status FROM v$asm_disk;
（4）若结果显示 Offline，则需要重新挂载磁盘：
ALTER DISKGROUP “DATA_HIG” ONLINE DISK “ZZS00234”;