Oracle VM Manager communicates with all storage through a set of plug-ins named Storage Connect. These plug-ins are not actually run from the Oracle VM Manager but rather live on some or all of the Oracle VM Servers. You can see these plug-in files in the local file system of an Oracle VM Server in the /opt/storage-connect/ directory. In the user interface of Oracle VM Manager you select an available plug-in when creating and configuring storage elements for use in your environment.
As you can see in the Storage tab of the Hardware view in Figure 4.1, “Storage tab in Hardware view”, storage elements are logically divided in File Servers and Storage Arrays. This distinction refers to the difference between file-based storage and block-based storage, or raw disks. Both types of storage are supported and Storage Connect plug-ins are available for each category described in Section 4.2, “Storage Types”.
Furthermore, Storage Connect plug-ins are split up according to the functionality they offer: there are generic plug-ins and non-generic plug-ins, also referred to as vendor-specific plug-ins. Generic plug-ins offer a limited set of standard storage operations on virtually all storage hardware, such as discovering and operating on existing storage resources. We categorize these operations as 'passive' in the sense that they do not interact with the storage management but simply detect the available storage architecture and allow it to be used in the Oracle VM environment.
Vendor-specific plug-ins include a much larger set of operations, which also includes direct, active interventions on the storage hardware: snapshot, clone, create LUNs, resize, and so on. To execute generic storage plug-in operations, only an access host or fibre channel connectivity is required (for iSCSI: typically a host name or IP address with a port number). The non-generic plug-in operations require an additional admin host, with optional administrative user name and password, granting Oracle VM Manager direct access to the configuration of the storage hardware.
