The system finds a place for the file on auxiliary storage. You
can specify where to store the file with the UNIT parameter.
Note: Effective for Version 3 Release 6 the UNIT parameter is a no-operation
(NOP) function for the following commands:
- Create Physical File (CRTPF)
- Create Logical File (CRTLF)
- Create Source Physical File (CRTSRCPF)
- Change physical File (CHGPF)
- Change Logical File (CHGLF)
- Change Source Physical File (CHGSRCPF)
The parameter can still be coded; its presence does not cause an error.
It will be ignored.
The
UNIT parameter specifies:
- The location of data records in physical files.
- The access path for both physical files and logical files.
The data is placed on different units if:
- There is not enough space on the unit.
- The unit is not valid for your system.
An informational message indicating that the file was not placed on
the requested unit is sent when file members are added. (A message is
not sent
when the file member is extended.)
UNIT parameter tips
In general,
you should not specify the UNIT parameter. Let the system place the file on
the disk unit of its choosing. This is usually better for performance, and
relieves you of the task of managing auxiliary storage. If you specify a unit
number and also an auxiliary storage pool, the unit number is ignored.