The Mechanical APDL program, by default, creates only one (sometimes large) file for each of the various file types. In the past, many systems had smaller disk partitions than were required for some of the very large files, or were limited to a maximum single file size of 2 GB. To accommodate this hardware limitation and provide the flexibility to store very large files across multiple disk systems, you can specify split file sizes and divide files across multiple disks.

By default, file are never split. You can, however, set your own file sizes for split files. The split file sizes are defined in units of Mwords (1024*1024 4-byte integer words).

You can enable file splitting for jobs using the FILESPLT directive in your config.ans file. (An alternative method is to use the /CONFIG,FSPLIT command.) The default setting within Mechanical APDL is the recommended option in almost all cases. File splitting will almost always increase run time, particularly if different disks are used for various file partitions. The best way to improve I/O performance on modern systems is by using multiple drives which are configured in a RAID0 striped configuration. (See the Performance Guide for more information on improving performance.)

To use the file-splitting feature, first determine a split point for your files. Then, any file types that can be split and are larger than that split point will be split across partitions. Select a split point carefully. Split files are less efficient than single files, and to reuse split files, you must match the split points correctly. Do not set your split point so low that small files would be split unnecessarily.

Figure 7.1: Determining Split Points illustrates one way to determine an appropriate split point. In this figure, if you chose split point 1, all of the file types would be split. If you chose split point 2, however, only two of the four file types need to be split.

Figure 7.1: Determining Split Points

You can split the following files. See the Basic Analysis Guide for file descriptions.

To split files across partitions, follow these steps:

In the above line, xxxx is the integer value indicating the file split point in megawords. With this config.ans file in place, the file will be split into a new file every increment of xxxx megawords. These files are all created in the current directory and are named Jobname.xxxnn, where XXX indicates the file extension (see list, above), and nn is a two-digit number from 02 to 99.

To place these files in different partitions, symbolically link the name Jobname.xxxnn to a pathname on another partition with the ln -s command in Linux. For example, to split a file.emat and write a second file to a different partition:

ln -s /tmp/file.EMAT02  file.EMAT02

The above example puts a second file.emat into the /tmp partition.

When you finish creating the appropriate symbolic links, you are ready to execute the Mechanical APDL program.

You cannot transport the split files to other systems.