Integrated File System Introduction
*TYPE2 directories
The "root" (/), QOpenSys, and user-defined file systems (UDFS) in the integrated file system support the *TYPE2 directory format. The *TYPE2 directory format is an enhancement of the original *TYPE1 directory format. *TYPE2 directories have a different internal structure and different implementation than *TYPE1 directories.
The advantages of *TYPE2 directories are:
- Improved performance
- Improved reliability
- Added functionality
- Less auxiliary storage space (in many cases).
*TYPE2 directories improve file system performance over *TYPE1 directories, especially when creating and deleting directories.
*TYPE2 directories are more reliable than *TYPE1 directories. After a system abnormally ends, *TYPE2 directories are completely recovered unless there has been an auxiliary storage failure. *TYPE1 directories may require the use of the Reclaim Storage (RCLSTG) command in order to recover completely.
*TYPE2 directories provide the following added functionality:
- *TYPE2 directories support renaming the case of a name in a monocase file system (for example, renaming from A to a).
- An object in a *TYPE2 directory can have up to one million links compared to 32,767 links for *TYPE1 directories. This means you can have up to 1 million hard links to a stream file, and a *TYPE2 directory can contain up to 1 million sub-directories.
- Using iSeries Navigator, the list of entries are automatically sorted in binary order when you open a directory that has the *TYPE2 format.
Typically, *TYPE2 directories that have less than 350 objects require less auxiliary storage than *TYPE1 directories with the same number of objects. *TYPE2 directories with more than 350 objects are ten percent larger (on average) than *TYPE1 directories.
There are several ways to get *TYPE2 directories on your system:
- A user-defined file system (UDFS) in an independent auxiliary storage pool (ASP) is converted to *TYPE2 format the first time the independent ASP is varied on to a system installed with OS/400 V5R2.
- All other supported file systems except UDFSs on independent ASPs must be converted to *TYPE2 by using the Convert Directory (CVTDIR) command.
- New iSeries servers that are pre-loaded with OS/400 V5R2 have *TYPE2 directories. No conversion is needed for "root" (/), QOpenSys, and UDFSs in ASPs 1-32.
- A scratch install of OS/400 V5R2 on an iSeries server has *TYPE2 directories. No conversion is needed for "root" (/), QOpenSys, and UDFSs in ASPs 1-32.
To determine the directory format for the file systems on your server, use the Convert Directory (CVTDIR) command:
CVTDIR OPTION(*CHECK).
- *TYPE2 directories are supported on OS/400 V5R1, but there are some differences from normal *TYPE2 directory support. For more information, see Using *TYPE2 directories in OS/400 V5R1.
For more information about *TYPE2 directories, refer to the following topics:
- Convert to a *TYPE2 directory
- "Root", QOpenSys, or UDFS unavailability
- Auxiliary storage requirements
- Symbolic link considerations
- Independent auxiliary storage pools (ASPs)
- Save/restore considerations
- Prepare for *TYPE2 conversion
- Conversion processing
- Example: Convert all file systems (small number of objects)
- Example: Convert all file systems (large number of objects)
- Example: Convert only certain ASPs
[ Top of Page | Previous Page | Next Page | Table of Contents | Index ]