In the Common Information Model (CIM) agent for the system, the
IBMTSSVC_StorageConfigurationService class provides all the methods that are required for creating,
modifying, and deleting an IBMTSSVC_StorageVolume
instance. This class creates the standard
volume; it also creates a thin-provisioning volume by using one of two methods: IBM extension
parameters, or the Storage Management Initiative – Specification (SMI-S). This procedure describes
the differences between the two methods.
To create a new IBMTSSVC_StorageVolume instance, follow these steps.
Apply the CreateOrModifyElementFromStoragePool() method on the IBMTSSVC_Cluster that you use to
create the new IBMTSSVC_StorageVolume, with these parameter specifications:- Virtualization Type: 0, 1, 2 for striped, sequential, or image.
- Format flag: specifies the volume is formatted on creation or expansion.
- BackendVolume REF: specifies the BackendVolumes to place the extents for
the volume.
- PreferredNode: sets the preferred node for the volume.
- UnitDeviceID: sets the volume's Unit Device ID on
clustered systems that are running software level 4.1.0 or higher.
- UnitDeviceID: sets the volume's Unit Device ID
on clustered systems.
- ElementName: sets the volume name at creation.
- Autoexpand:
- Set the ElementType
- An ElementType of 2 with the Standard Goal parameter
creates a standard storage volume.
- An ElementType of 8 creates a compressed storage volume.
- Set Size to the preferred volume size in bytes.
- Obtain the reference (CIMObjectPath) of the IBMTSSVC_ConcreteStoragePool instance from which
you allocate an IBMTSSVC_StorageVolume.
- Set InPool to the reference (obtained in the previous step) of the pool from which the volume
is allocated.
The creation of a thin-provisioning volume based on SMI-S is available. To set the initial
reserve value, use the Goal parameter only if the initial reserve value of the
volume is not the default reserve value (0 KB). The instance of IBMTSSVC_StorageVolumeSetting is
required to be created by IBMTSSVC_StorageConfigurationCapabilities::CreateSetting(). After the
creation, modify the initial reserve value of this instance. The newly created instance will be
taken as the Goal parameter to create the standard volume, and will be deleted
automatically after 20 minutes.
The following examples are parameters that are also available as part of the Volume Mirroring
feature or Thin-Provisioned Volume feature.
- Autoexpand
- Used to attempt to maintain a fixed amount of unused real capacity on the volume, which is
called the contingency capacity. The capacity is initially set to the real
capacity, which is assigned when the volume is created. If you modify the real capacity, the
contingency capacity is reset to be the difference between the used capacity and the
real capacity.
- Copies
- Indicates the number of mirrored copies to create. Specify either 1 or 2.
- Grainsize
- Sets the grain size of a thin-provisioned volume, which is valid only if RealSize is set. Valid
options include 32, 64, 128, or 256.
- Import
- Used to request that the system import a thin-provisioned storage volume from the storage pool.
- IsSpaceEfficient
- Flag that is used to indicate that the created volumes are thin-provisioned volumes. This flag
does not apply to a modify operation.
Important: If the ElementType is set as 5, do not
set this parameter.
- RealSizeBytes and RealSizePercent
- Indicates the real size of a thin-provisioned copy. These parameters cannot be used
together.
Important: If the ElementType is set as 5, do not set this
parameter.
- WarningSizeBytes
- Indicates the set point of used capacity at which point a warning is triggered. This parameter
cannot be used with the WarningSizePercent parameter.
- WarningSizePercent
- Indicates the ratio of used capacity versus the volume virtual capacity that triggers a warning.
This parameter cannot be used with the WarningSizeBytes parameter.
- AccessIOGrpList
- Indicates the storage volume's access IO group list.