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XaaS                                                     3


                                                         Use case

             Description          –  CSC configures the backup policy for the VM, and the policy could be weekly backup.
                                  –  CSP performs the backup operation according to the policy the CSC configured.
                                  –  CSP detects that the VM becomes faulty or its data is lost, CSP recovers the VM using
                                     backup automatically without CSC's awareness.
             Requirements         –  VM backup (refer to clause 7.1.7)


            I.4     IaaS storage service use case

                                                         Use case
             Name                 IaaS use case on storage

             Abstract             CSC uses block, file or object storage directly or attach to the virtual machine provided by
                                  the CSP
             Roles                CSC, CSP
             Figure                              CSC

                                                                                     CSP









                                                                             Storage       Computing
                                                                             resource pool  resource pool
                                                                    Portal
                                                                                Cloud infrastructure
                                                                                                 Y.3513(14)_FI.4
             Pre-conditions       –  CSC accesses the IaaS through the portal with appropriate security mechanism and
             (optional)              retrieves the functions exposed that are related to storage and attached computing, if
                                     needed.
             Post-conditions

             (optional)
             Description          –  CSC accesses and queries the CSP portal to retrieve the list of supported functions
                                     related to storage functions.
                                  –  CSC selects the appropriate storage from the query results and requests the CSP to
                                     create block, file or object storage based on the selection.
                                  –  CSP creates block, file or object storage from the storage resource pool based on the
                                     information provided by the CSC.
                                  –  CSC attaches the created storage to specified virtual machine if needed.
                                  –  CSC manages and monitors the created storage during its lifecycle. It includes, but not
                                     limited to:
                                     •  create, attach, detach, query and delete a volume of storage at either block level or
                                        file-system level;
                                     •  write, read and delete data;
                                     •  query the storage information and its status;
                                     •  set migration or I/O limitation policies;
                                     •  execute performance metrics;
                                     •  snapshot or backup the storage;
                                     •  reservation storage resource.





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