The dL4 Logical Unit Search Table (DL4LUST) searches each directory in the search table to locate a file. The search continues with the next search table entry until the file is either located or the end of search table is reached.

Unlike DL4LUST, LUMAP does not use a search mechanism. Instead, it maps a relative file path to an absolute file path using a mapping mechanism. For example, if LUMAP had the value "data=/usr/files", then the relative path "data/customer" would be mapped to the absolute path "/usr/files/customer". If a mapping is found in LUMAP when opening a file and the file is not found, the "File not found" error will be reported without searching for or mapping additional paths.