As just described, a user with appropriate privileges can use ulimit(1) to set the ulimit value discretely, up to 2GB. The ulimit(1) command also supports large files, but cannot set values discretely beyond 2GB.
ulimit values larger than 2GB and up to a file's maximum size, can be set by executing
ulimit -f unlimited
The string unlimited requests the largest valid limit, whatever it is on your system. For large-file-aware filesystems, unlimited represents the largest file size for the filesystem. See Intro(2) for more information on large file support.