About Storage Computation Formulas

In all the formulas presented on this page, shared storage is accurately counted once when the storage is accessible from multiple systems or accessible through multiple physical paths on the same system. Globally unique identifiers have been instrumented for accurate counting of shared storage.

Computations for the summary attributes presented in the Storage Details page are listed in the following sections.

• Computations in Overall Utilization Chart

• Computations in Provisioning Summary Chart

• Computations in Consumption Summary Chart

• Computations in Vendor Distribution Property Page

Computations in Overall Utilization Chart

The attributes reflected in the Overall Utilization chart are calculated as follows:

• Unallocated storage for associated hosts equals (=)

  Unallocated storage for Disks 
  + Unallocated storage for Volumes 
  + Unallocated storage for ASM

• Overhead for associated hosts equals (=)

  Sum of the size of all Disks 
  + Sum of the size of all writable NFS mounts 
  - (Allocated Storage for associated hosts 
     + Unallocated Storage for associated hosts)

• Free storage for associated hosts equals (=)

  Free Storage for the Databases 
  + Free Storage for Local File Systems 
  + Free Storage for Writeable NFS

• Used Storage for associated hosts equals (=)

  Allocated Storage for associated hosts 
  - (Free Storage for Databases + Free Storage for Local File Systems 
  + Free Storage for Writeable NFS)

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Computations in Provisioning Summary Chart

The attributes reflected in the Provisioning Summary chart are calculated as follows:

• Allocated storage for disks equals (=)

  Sum of the size of all allocated entities in disk layer

• Allocated storage for Volumes equals (=)

  Sum of the size of all allocated top-level entities.

• Allocated storage for ASM equals (=)

  Total size of storage space allocated to Oracle databases from ASM

• Allocated storage for Writeable NFS equals (=)

  Sum of the size of distinct Writeable NFS mounts

• Unallocated storage for Disks equals (=)

  Sum of the size of unallocated space in all the disks

• Unallocated storage for Volumes equals (=)

  Sum of the size of unallocated space in all top-level, intermediate and 
  bottom-level entities

• Unallocated storage for ASM equals (=)

  Total storage available for allocation to the database layer from ASM

• Overhead for Volumes equals (=)

  Sum of the size of all bottom-level entities 
  - Allocated Storage for Volumes 
  - Unallocated Storage in Volumes

• Overhead for ASM equals (=)

  Sum of the size of all disks in ASM layer 
  - Allocated Storage for ASM 
  - Unallocated Storage for ASM

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Computations in Consumption Summary Chart

The attributes reflected in the Consumption Summary chart are calculated as follows:

• Used Storage for Databases equals (=)

  Total storage used in the database Tablespaces 
  + Size of all control files 
  + Size of all redo log file

• Used Storage for Local File Systems equals (=)

  Total storage used in all local file systems

• Used Storage for Writeable NFS equals (=)

  Total storage used in all Writeable NFS mounts

• Free storage for the Databases equals (=)

  Sum of the size of the databases 
  - total used storage in the databases

• Free storage for Local File Systems equals (=)

  Sum of free space in all distinct local file systems

• Free storage for Writeable NFS equals (=)

  Sum of free space in all distinct Writeable NFS

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Computations in Vendor Distribution Property Page

The attribute reflected in the Vendor Distribution property page is calculated as follows:

• Host-Visible Storage for associated hosts equals (=)

  Sum of the size of all disks 
  + Sum of the size of all Writeable NFS mounts

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Related Topics

About Storage Details

About Storage Layers

About Disks

About Volumes

About File Systems

About Databases

About ASM

About Hosts

Enterprise Manager Information Roadmap

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