Một dịch vụ web RESTful là một dịch vụ web đơn giản được thực hiện bằng cách sử dụng HTTP và các nguyên tắc của REST. Một dịch vụ web có thể được dùng như một tập hợp các nguồn lực bao gồm ba khía cạnh: 1. 2. 3. URI cho các dịch vụ web kiểu MIME của dữ liệu được hỗ trợ bởi trang web | 268 Cloud Computing Figure The Virtual Media Manager. If you previously created any virtual hard disks which have not been attached to other virtual machines you can select from among those using the drop-down list in the Wizard window. Since we have downloaded and extracted a new image of OpenSolaris it will not be included in the list. Click on the Existing. button to continue on to the Virtual Media Manager as shown in Figure . In this figure OpenSolaris is not listed as an available selection. Since it is not listed we need to add it by clicking on the Add button at the top of the dialog. The Virtual Media Manager keeps an internal registry of all available hard disk CD DVD-ROM and floppy disk images. This registry can be viewed and changed in the Virtual Disk Manager which you can access from the File menu in the VirtualBox main window. The Disk Image Manager will show you all images that are registered with VirtualBox grouped in three tabs for the three supported formats. These are hard disk images either in VirtualBox s own Virtual Disk Image VDI format or in the widely supported Virtual Machine DisK VMDK format. CD and DVD images in standard ISO format are also supported. There is support for floppy images in standard RAW format. As shown in Figure for each image the Virtual Disk Manager shows the Appendix A 269 Figure Figure The Select a hard disk image file dialog. 270 Cloud Computing Figure Back to the Virtual Hard Disk dialog. full path of the image file and other information such as the virtual machine to which the image is currently attached if any. Clicking the Add button will bring you to the Select a hard disk image file dialog as shown in Figure . Use this file dialog to navigate to the VirtualGuests folder. In the VirtualGuests folder open the VDI folder and highlight the file. Once you have highlighted it simply click on the Open button to continue. You will be returned to the Virtual Hard Disk .