A valid backup is a backup that will allow you to restore your database.When using an OS utility (cpio, tar, ..) to backup your database then it is important that . your database is shutdown and is not accessed by any single-user client all the time the backup takes place . you do not miss any file of your databaseThe database files will be just a <dbname>.bi and <dbname>.db for Progress V8 (as well as V6 and V7) single volume database, but there are more files for any V9 database or for multi-volume databases. For a multi-volume database, the command "prostrct list <dbname>" will give you the list of its files.. You will find in the "<database>.st" file the localization of:<dbname>.b1, <dbname>.b2, ....<dbname>.bN [ Primary Recovery Area, also called Before Image file ] <dbname>.d1, <dbname>.d2, ....<dbname>.dX [ Schema Area ]<dbname>_7.d1, <dbname>_7.d2, ..... [ User Area #7]...<dbname>_I.d1, <dbname>_I.d2, ..... [ User Area #I]Make sure your have on your OS backup all the above files, plus the file <dbname>.db [ Control Area ].For version 8, you will have no User Area, i.e. no file <dbname>_I.dJ.The files<dbname>.a1, ... <dbname>.aM [ After Image Area ]<dbname>.t1,... <dbname>.tN [ Transaction Log Area ]do not need to be included within your "database backup".