The IFS is the INTEGRATED FILE SYSTEM that now exists on the AS400. The easy way to access this is to load iseries navigator (do custom and select all options). Then go to the FILE SYSTEM tab. From here you can create folders that users can save files to and have them backup using the AS400. It is a great option and you should definitely research it.
The IFS (Integrated File System) is how IBM named the way that AS/400s handle different file systems within a single system image.
On a Windows PC, you might have two disk drives. One drive might be formatted for NTFS and another might be FAT32. You might also have a diskette drive that uses diskettes formatted with a FAT file system. Those are three different file systems with different characteristics and capabilities. But Windows Explorer handles all three at once in an integrated fashion.
That’s similar to what is called the IFS on AS/400s.
/QDLS is a kind of FAT file system.
/root is more like NTFS.
/QSYS.LIB is the common database file system.
/QOpenSys is a Unix file system.
There are a number of other file systems integrated with those within a single system image. An easy way to see all of the active file systems at once is with the WRKLNK command. iSeries Navigator provides a PC GUI view. The “IFS” provides a common naming format and allows a single program to access objects in all of the file systems at once, using methods native to each file system or methods that are valid for all file systems.
The structure makes it possible for IBM to plug new file systems in as needed whenever they are created. (You can even create your own.) New devices such as for solid-state storage can be accessed natively, even without recompiling programs.
Overall, everything in storage is within one of the file systems in the IFS. You won’t work with anything that isn’t in the IFS.