The following example demonstrates how du and ls can differ because setext was used to pre-allocate or reserve space for a file and how to use setext-r to resolve the difference.

1.  Create a file and check its size using ls and du .  Note that both commands show 0 bytes:
 

 

 

2.  Use setext to pre allocate space for the file and check ls and du again.  Note this time du shows 1024 Kbytes allocated to the file while ls still shows 0 bytes:
 

 

 

3.  The getext command can be used to check the space reservation of a file:
 

4.  The setext command also can be used to clear a space reservation for a file:
 

 

 

A relatively common occurrence of a file with a space reservation is a VERITAS Quick I/O file for a database like Oracle. A file that is created as a Quick I/O file by qiomkfile will have a space reservation associated with it. Even if this file is converted to a regular VERITAS FileSystem (VxFS) file, the space reservation will persist. However, a file that is converted from a regular VxFS file to Quick I/O manually or using the conversion script will not have a space reservation associated with it.