Many cases where a process becomes suspended by the system can be prevented with a little planning. To be sure, there are situations that cannot be anticipated that might make it necessary for the system to suspend a process. One such example is an extreme shortage of available memory. However, a good many cases of process suspension result from such causes as failed attempts to open files or ACCEPT statements that require immediate input from the operator.

In many of these cases, it might be preferable to allow the process to become suspended. The advantage to this is that the process appears in the W (Waiting Mix Entries) display with a message explaining why it is suspended. This is desirable if the situation is one that an operator can easily remedy. A common example of such a situation is one where a process is attempting to open a tape file. When the process appears in the W display, the operator is prompted to mount the appropriate tape.

However, if you are interested in automating operations at your site as much as possible, then you might find the techniques discussed in the following subsections to be useful. For further information about the file attributes mentioned in the following discussions, refer to the File Attributes Programming Reference Manual.