A permanent data object is a virtual storage access method (VSAM) linear data set that resides on DASD. (This type of data set is also called a data-in-virtual object.) You can read data from an existing permanent object and also update the content of the object. You can create a new permanent object and when you are finished, save it on DASD. Because you can save this type of object on DASD, window services calls it a permanent object. Window services can handle very large permanent objects that contain as many as four gigabytes (4294967296 bytes).