Virtual disk models
Key attributes of BMC_LogicalDisk virtual disk
The following table describes the key attributes of a virtual disk:
Attribute | Usage |
|---|---|
Name | Identifies the logical disk that is allotted to the virtual machine. The following list provides examples of the values that the Name attribute might contain, depending on the operating system:
|
NameFormat | The heuristic method that is used to generate the Name value. When this attribute is set to OS Device Name, the Name attribute is populated with a uniquely identifiable device name. |
SystemName | The name of the computer system to which the logical device belongs. |
Additional attributes of BMC_LogicalDisk class
The following table describes additional attributes of a virtual disk:
Attribute | Description |
|---|---|
BlockSize | Size of the blocks (in bytes) that form the given storage extent. If the block size is a variable, specify the maximum block size in bytes. If the block size is unknown, specify a value of 1. |
NumberOfBlocks | Total number of logical contiguous blocks that form the given storage extent. You can calculate the total size of the storage extent by multiplying the BlockSize by the value of the NumberOfBlocks attribute. If the BlockSize is 1, this property is the total size of the Extent. |
AvailableCapacity | Indicates the total amount of free space (in bytes) that is available on the given storage extent. If the free space is unknown, specify a value of 0. |
ConnectionType | The storage protocol that is used to communicate with the storage controller, for example, SCSI, iSCSI, FCoE, and Infiniband. |
Virtual disks allocated to virtual machines
Model the virtual disk allocated to a virtual machine (VM) by using the BMC_LogicalDisk class and create an association to the VM by using the SYSTEMDEVICE relationship.
The following figure illustrates a simple scenario where a virtual disk is allocated to a VM and a file system is installed on it:
Logical disks allocated to a virtual machine from a resource pool
You can model storage resources that are allocated from the storage resource pool by using the BMC_ResourcePool class. This class has attributes to store capacity and utilization properties of the storage resources. The resource pool must be related to the storage system that hosts it by using the HOSTEDRESOURCEPOOL relationship.
You may have one or more virtual disks in your environment that are created from a storage system and are allocated to virtual machines. You can use the BMC_LogicalDisk class to model such virtual disks. You can use the SYSTEMDEVICE relationship to associate this class to the hosted virtual machine and the ELEMENTALLOCATEDFROMPOOL relationship to associate the logical disk to the resource pool to which it belongs.
You must model the file system laid by the virtual computer system on the logical disk by using the BMC_LocalFileSystem class. You must associate this class to the logical disk by using the RESIDESON relationship. Associate the BMC_ComputerSystem class by using the HOSTEDFILESYSTEM relationship.
The following figure illustrates an example of a logical disk that is allocated from a resource pool and is hosted on a storage system:
