If you enable wrapping trace, you can use the -b switch when you issue the cicscli command to turn tracing on. This specifies that memory mapped trace files should be used.
With memory mapped tracing, the operating system's paging mechanism is used to swap data between memory and the trace file. This improves performance significantly when compared to standard file I/O, because the trace file is opened and written to less frequently. Because the operating system is responsible for flushing data to disk, data is not normally lost if an application terminates unexpectedly. However, if the operating system itself fails, data can be lost, and the trace file can be corrupted. If you are diagnosing problems where the server fails and needs to be restarted, use standard I/O tracing instead of memory mapped tracing.
If you use memory mapped tracing, the size of the trace files is limited to 10 MB, and in addition to cicscli.bin and cicscli.wrp, you might see a series of files of the form cicscli.wrp1, cicscli.wrp2...cicscli.wrpn, where n is the number of files needed to hold the total amount of trace data specified in the Client trace file wrap size (KB) field of the Configuration Tool; see Client trace file wrap size (KB) for the maximum amount of data that can be specified. The trace formatter finds all files in the sequence when you format the binary files. Memory mapped tracing uses up to 10 MB of virtual storage.
See Starting client tracing for details of how to issue the command, and Security considerations for trace and log files for important information on security.