Oracle 12c之前的版本中，ASM磁盘组中单块磁盘大小不能超过2T，当创建磁盘组单盘大小超过2T时就会报错。 但是从Oracle 12c开始，Oracle引入了一个名为“大表空间”（Bigfile Tablespace）的概念，它允许单个表空间的最大容量达到数百TB甚至更多。使用大表空间，您可以创建超过2TB的表空间来存储数据。

哪里也没说最大2T，不知道那文章从哪里得到的说法？

What Is The Maximum Tablespace Size And Database Limit For An Oracle Database ? (Doc ID 1372905.1)

Small file database

For a small file database, the Oracle database has the following limits :

maximum number of datafiles is : 65533
maximum data blocks per datafile : 2^22 -1 = 4194303
maximum datafile size = db_block_size * maximum number of blocks
maximum db_block_size = 32 K
maximum tablespace size = 1022 * max database file
Resulting values are:

maximum datafile size = 32 * 4194303 = 128 GB
maximum tablespace size = 1022 * 128 GB = 130816 GB
maximum database size = 128 G * 65533 = 8388224 GB

Big file database

For a big file database, the Oracle database has the following limits :

maximum number of datafiles is : 65533
maximum data blocks per datafile : 2^32 = 4294967296
maximum datafile size = db_block_size * maximum number of blocks
max db_block_size = 32 K
maximum tablespace size = size of big datafile
Resulting values are:

maximum datafile size = 32 * 4294967296 = 128 TB
maximum tablespace size = 128 TB
maximum database size = 128 T * 65533 =8388224 TB

Note:

If you tried to increase the maxsize of a datafile to beyond the limits explained in this document the operation will fail with ORA-3206 error.

Oracle does no support datafile size with 4294967296 blocks, it will lead to the ORA-00740 error as follows.

ORA-00740: datafile size of (4294967296) blocks exceeds maximum file size
复制

Typically it should be reduced by 1 block as 4294967295.