By default, *.cmp files are limited to 24 MB in size, although you can change this using the FileMaxSize property. If set to zero, the value resets to the default.

When site data exceeds the specified limit, site data is separated in to two or more migration files. However, if a single site data file exceeds the maximum file size, the operation does not split the source file, but rather it resizes the .cmp file to accommodate the oversize file. You can have any number of .cmp files.

The range of allowable size values for the .cmp file is from 1 MB to 2GB. If you specify a value that is outside this range, the export operation reverts to the default value of 24 MB.