The Server Manager builds a topology of the managed ScaleIO entities. The topology objects represent the managed ScaleIO elements in the network, their relationships, and their connections. Topology objects include:

  • DataStorageService — Represents the module that provides storage. A lightweight software component that is installed on each server which contributes to the ScaleIO storage.

  • StorageClientService — Represents the module that provides access to storage. The StorageClientService is a lightweight block device driver that exposes ScaleIO shared block volumes to applications.

  • StorageManagementService — Represents individual storage service management module. The MDM serves as the monitoring and configuration agent of the ScaleIO system. The MDM is mainly used for management which consists of migration, rebuilds, and all system-related functions. To support high availability, three or more instances of MDM run on different servers. In a multi-MDM environment, one MDM is given the primary role, and the others act as secondary or TieBreaker MDMs.

  • StorageManagementServiceGroup — Represents cluster of modules that manages storage service. The MDM cluster comprises a combination of primary MDM, secondary MDMs, and TieBreaker MDMs.

  • StoragePool — A Storage Pool is a set of physical storage devices in a Protection Domain. Each storage device belongs to one (and only one) Storage Pool. To provide consistent performance it is recommended that all devices in the StoragePool will have similar storage properties.

  • StorageProvider — Represents the ScaleIO instance in the Server Manager. This basically groups different modules responsible for providing and managing storage offering provided by ScaleIO.

  • StorageServiceGroup — Represents the ScaleIO protection domains.

  • StorageVolume — Represents the logical storage volume in the ScaleIO system. A volume consists of multiple blocks spread evenly on a storage pool devices. Volumes are defined within a Storage Pool, and then exposed to the applications as local storage device using the SDCs.

  • StorageGatewayService — Represents the module that provides Gateway to StorageProvider.

  • StorageServiceFaultGroup — Represents the logical grouping of the data storage services offered.

  • PhysicalDisk — Represents the physical disk either from a storage array or directly attached to host. ScaleIO works with any free capacity—internal or direct-attached devices, either magnetic hard disk drives (HDD) or flash-based devices such as solid state drive (SSD) and PCIe cards.


    Any physical disk removed and added back through ScaleIO GUI, then added physical disk is considered as new object and a new unique ID is assigned. So the user must perform a rediscovery of the ScaleIO host in ESM. This behavior is applicable to all the ScaleIO components removed and added back in ScaleIO GUI. Post addition in ScaleIO GUI rediscovery of ScaleIO host is needed for monitoring to work properly.

    In addition, for the ScaleIO, the Smarts Server Manager uses topology objects like the VirtualInterface class, and the VirtualMachine class that the VMware Management feature discovers.