Hewlett-packard Development Company, L.p.

Hewlett Packard Enterprise Development LP

Vikram Krishnamurthy

Vijay Srinath

Subramaniyam V Pooni

Rajkumar Mangalore

Abhijit Chaudhuri

Vijay Ram Sevagapandian

A storage space management system for a thin provisioned virtual environment may comprise an over-allocation computation engine to compute an over-allocation metric for a virtual datastore. The over-allocation metric may be computed based on virtual storage space allocated to corresponding virtual machines and actual physical storage allocated to the virtual datastore. Further, the over-allocation metric may indicate extent of over-allocation of the actual physical storage to the virtual datastore. An available space computation engine may determine an available space metric for the virtual machines based on available datastore space and available physical storage space. An analysis engine may obtain a time value indicating time left within which storage space available for the virtual machines would be utilized. Further, the analysis engine may provide the over-allocation metric, the available space metric, and the time value to a capacity planning unit for storage space management in the virtual environment.

Storage space management in a thin provisioned virtual environment

The method and apparatus is utilized in order to generate a persistent path to a SCSI device for a host. In an embodiment, a SCSI device is queried for path information related thereto, and if path information is returned, a SCSI command requesting identifier data is issued to the SCSI device. The identifier data is used to determine a unique identifier (UID), from which is generated a UID-based device file for the SCSI device that is independent from the path information.

Method and apparatus for generating persistent path identifiers

A method, by which a user mode application obtains all physical paths that point to a logical unit on a newly-discovered small computer system interface (SCSI) device, may include: sending an input output control command to a kernel component regarding future discovery of any SCSI device; awaiting discovery of a new SCSI device; awaiting generation, by the kernel component, of a unique identifier (UID) and at least one set of physical path information mapping thereto for a logical unit on the newly-discovered SCSI device; and receiving, from the kernel component, the UID and the at least one set of physical path information mapping thereto for the logical unit of the newly-discovered SCSI device.

Method and apparatus for identifying multiple paths to discovered SCSI devices and specific to set of physical path information

The method includes querying for one or more logical unit numbers (LUNs) pertaining to a small computer system interface device, each LUN representing a potential path from a host to the SCSI device. Response data indicative of multiple LUNs to the single SCSI device is treated as separate instances of independent SCSI devices, with each separate instance representing a different SCSI separate instances of independent SCSI devices, with each separate instance representing a different SCSI device structure. A unique identifier (UID) is calculated for each SCSI device structure, from which a device file is generated based on the UID and contains UID and path information that differentiates between multiple paths from the host to the SCSI device.

Method and apparatus for identifying multiple paths to a SCSI device using a calculated unique identifier

A method and arrangement, for use in a system having a host and one or more small computer system interface (SCSI) devices, are described for enabling a user application accessing the system to communicate with one or more of the SCSI devices. The method and arrangement serve to overcome a device node limitation observed in standard Linux, which limits the number of devices a user application may communicate with to 128 SCSI disk (sd) devices or 256 SCSI generic (sg) devices. The method and arrangement provide a pass through capability by allowing the user application to directly talk to any SCSI device by using virtual handles, thereby overcoming the device node limitation observed in standard Linux.

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Bengaluru, India

Vikram Krishnamurthy