Storage Administration - Oracle Exadata Recipes: A Problem-Solution Approach - page 281

9-10. Setting smart_scan_capable on ASM Disk Groups
Problem
You wish to configure your ASM disk groups to either enable or disable Exadata Smart Scan processing.

Solution
In this recipe, we will show you how to use the smart_scan_capable ASM disk group attributes to influence whether
Exadata Smarts Scan will be enabled for I/O access to the extents resident on the disk group's files. Specifically, you
will learn how to create an ASM disk group with Smart Scan enabled, how to create with Smart Scan disabled, how to
alter your setting with the alter diskgroup command, and how to validate smart scans in both cases.

First, log in to your ASM instance as SYSASM and create an ASM disk group with cell.
smart_scan_capable set to TRUE :

1.

SQL> create diskgroup DATA_CM01
normal redundancy
disk 'o/*/DATA*'
attribute 'compatible.rdbms' = '11.2.0.3.0',
'compatible.asm' = '11.2.0.3.0',
'cell.smart_scan_capable' = 'TRUE',
'au_size' = '4M';

Diskgroup created.

SQL>

The cell.smart_scan_capable configuration is an ASM disk group attribute and is configured using the
attribute clause in the example above.

2. To create an ASM disk group with Smart Scan disabled, use the

'cell.smart_scan_capable'='FALSE' syntax:

SQL> create diskgroup SDATA_CM01
normal redundancy
disk 'o/*/SDATA*'
attribute 'compatible.rdbms' = '11.2.0.3.0',
'compatible.asm' = '11.2.0.3.0',
'cell.smart_scan_capable' = 'FALSE',
'au_size' = '4M';

Diskgroup created.

SQL>

To modify your current disk group attribute, connect to your ASM instance as SYSASM and
use the following alter diskgroup command:

3.

[grid@cm01dbm01 ~]$ sqlplus / as sysasm

SQL*Plus: Release 11.2.0.3.0 Production on Fri Sep 14 01:29:21 2012