Configuration of Oracle Automatic Storage Management for VLDBs is not very different from Oracle ASM configuration for non-VLDBs. Certain parameter values, such as the memory allocation to the Oracle ASM instance, may need a higher value.
Oracle Database supports Oracle ASM variable allocation units. Large variable allocation units are beneficial for environments that use large sequential I/O operations. VLDBs in general, and large data warehouses in particular, are good candidate environments to take advantage of large allocation units. Allocation units can be set between 1 MB and 64 MB in powers of two (that is, 1, 2, 4, 8, 16, 32, and 64). If your workload contains a significant number of queries scanning large tables, then you should use large Oracle ASM allocation units. Use 64 MB for a very large data warehouse system. Large allocation units also reduce the memory requirements for Oracle ASM and improve the Oracle ASM startup time.
Oracle Automatic Storage Management Administrator's Guide for information about how to set up and configure Oracle ASM