HP 3000 Manuals

Volume Management

Creating Files 

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.

   *   File extents.

   *   File restriction.

File Opening 

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 

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 

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 

MPE/iX 5.0 Documentation