Once the account structure exists, you can use or build files. Building files is described in detail in Controlling System Activity (32650-90155).
This section describes the following file building information specific to volume management.
File Opening |
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When opening a file, the system searches for the file in the system directory root, traversing down to the group/file node, which points to the directory root on the nonsystem volume. The system then traverses this tree to find the file. However, this process only happens when a file is first accessed. All further reads and writes go directly to the file.
File Extents |
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A file's extents may be spread across the volumes within a volume set. If you are using volume classes, you have to specify the volume class restriction at the time you create the file.
A master volume is needed when the file is opened because the volume set directory is on the master volume and the directory is needed to find the file's extents.
File Restriction |
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Files can be restricted to a particular volume class or volume by using the HPFOPEN intrinsic. Refer to the MPE/iX Intrinsics Reference Manual (32650-90028) for more information.
Figure 3-5 Building Files
![[Building Files]](img/LG200047_016.gif)
