In ORACLE database, especially RAC, the underlying storage uses ASM. In the maintenance of the ORACLE database stored in ASM,
There is a situation prone to initialize a table space or create multiple data files at one time. In fact, the ASM disk group can accommodate
The number of data files is easily limited by the ASM disk group. For example, a 1TB ASM disk group can hold up to 1TB*1024/32G, etc.
For 34 data files, more than 34 data files may cause the capacity of the ASM disk group to overflow. ASM disk group capacity overflow situation
As shown in the figure below:
Look at the negative number of usable_file_MB in DATADG above, is it Oracle's calculation wrong, in fact, it is not, it is the data file of the table space
The maximum space capacity of the file exceeds the maximum capacity of the DATADG disk group. After this situation occurs, it will lead to a table space
The utilization rate may not reach 100%, but the table space cannot be written to, and once the disk slot that can be inserted into the back-end storage is full,
Easily lead to a table space data file must be migrated from the problem ASM disk group to another disk group.
This situation is relatively simple to solve. If storage is allowed, add disks to the problem ASM disk group until usable_file_MB is a positive number.
Ensure that the disk group can accommodate the maximum space of the existing data files; if storage is not allowed, it is recommended to add an ASM disk group and use RMAN to
Some data files are migrated from the problem disk group by rename.