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Disk Group Attributes

Disk group attributes are parameters that are bound to a disk group, rather than an Oracle ASM instance.

Disk group attributes can be set when a disk group is created or altered, unless otherwise noted in the following list.

• ACCESS_CONTROL.ENABLED

  This attribute can only be set when altering a disk group.

  For information about theACCESS_CONTROL.ENABLEDattribute, see"Setting Disk Group Attributes for Oracle ASM File Access Control".

• ACCESS_CONTROL.UMASK

  This attribute can only be set when altering a disk group.

  For information about theACCESS_CONTROL.UMASKattribute, see"Setting Disk Group Attributes for Oracle ASM File Access Control".

• AU_SIZE

  This attribute can only be set when creating a disk group.

  For information about allocation unit size and extents, see"Allocation Units","Extents", and"Specifying the Allocation Unit Size". For an example of the use of theAU_SIZEattribute, seeExample 4-1, "Creating the DATA disk group".

• CELL.SMART_SCAN_CAPABLE

  This attribute is only applicable to Oracle Exadata storage.

  See Also:

  Oracle Exadata documentation

• COMPATIBLE.ASM

  For information about theCOMPATIBLE.ASMattribute, see"COMPATIBLE.ASM".

• COMPATIBLE.RDBMS

  For information about theCOMPATIBLE.RDBMSattribute, see"COMPATIBLE.RDBMS".

• COMPATIBLE.ADVM

  For information about theCOMPATIBLE.ADVMattribute, see"COMPATIBLE.ADVM"and"Overview of Oracle ASM Dynamic Volume Manager".

• CONTENT.TYPE

  TheCONTENT.TYPEattribute identifies the disk group type:data,recovery, orsystem. The type value determines the distance to the nearest neighbor disk in the failure group where Oracle ASM mirrors copies of the data. The default value isdatawhich specifies a distance of 1 to the nearest neighbor disk. A value ofrecoveryspecifies a distance of 3 to the nearest neighbor disk and a value ofsystemspecifies a distance of 5.

  The attribute can be specified when creating or altering a disk group. IfCONTENT.TYPEattribute is set or changed usingALTERDISKGROUP, then the new configuration does not take effect until a disk group rebalance is explicitly run.

  TheCONTENT.TYPEattribute is only valid for disk groups that are set to normal or high redundancy. TheCOMPATIBLE.ASMattribute must be set to11.2.0.3or higher to enable theCONTENT.TYPEattribute for the disk group.

  The attribute can be set with SQL, ASMCMD, or ASMCA. For example:

  SQL> CREATE DISKGROUP data NORMAL REDUNDANCY
          FAILGROUP controller1 DISK
          '/devices/diska1' NAME diska1,
  ...
          ATTRIBUTE 
          'compatible.asm' = '11.2.0.3', 
          'content.type' = 'recovery',
  ...
  
  SQL> ALTER DISKGROUP data SET ATTRIBUTE 'content.type' = 'data';

  This attribute is primarily intended for use with Oracle Exadata storage.

  See Also:

  Oracle Exadata documentation

• DISK_REPAIR_TIME

  This attribute can only be set when altering a disk group.

  For information about theDISK_REPAIR_TIMEattribute, see"Oracle ASM Fast Mirror Resync".

• IDP.BOUNDARY andIDP.TYPE

  These attributes are intended for use with Oracle Exadata storage.

  See Also:

  Oracle Exadata documentation

• SECTOR_SIZE

  This attribute can only be set when creating a disk group.

  For information about theSECTOR_SIZEattribute, see"Specifying the Sector Size for Drives".

• STORAGE.TYPE

  TheSTORAGE.TYPEdisk group attribute specifies the type of the disks in the disk group. The possible values areAXIOM,ZFSSA, andOTHER. If the attribute is set toAXIOMorZFSSA, then all disks in the disk group must be of that type. If the attribute is set toOTHER, then any types of disks can be in the disk group.

  If theSTORAGE.TYPEdisk group attribute is set toAXIOMorZFSSA, then functionality for Hybrid Columnar Compression (HCC) can be enabled for Pillar Axiom or ZFS storage.

  Note:

  ZFS storage must be added through Direct NFS (dNFS) and Pillar Axiom storage must be added as SCSI/Fiber Channel.

  To set theSTORAGE.TYPEattribute, theCOMPATIBLE.ASMandCOMPATIBLE.RDBMSdisk group attributes must be set to11.2.0.3or higher. For information about disk group compatibility attributes, refer to"Disk Group Compatibility".

  TheSTORAGE.TYPEattribute can be set when creating a disk group or when altering a disk group. The attribute cannot be set when clients are connected to the disk group. For example, the attribute cannot be set when an Oracle ADVM volume is enabled on the disk group.

  The attribute is not visible in theV$ASM_ATTRIBUTEview or with the ASMCMDlsattrcommand until the attribute has been set.

  See Also:

  Oracle Database Conceptsfor more information about Hybrid Columnar Compression. Hybrid Columnar Compression is a feature of certain Oracle storage systems.