The IBMi I.F.S. (Integrated File System) is a terrific part of the operating system which lets us consolidate our native IBMi data and give access to it from other, different, file systems. It lets us access Native IBMi data from internal and external processes. The IFS is a repository for different types of data that native IBMi users or disparate network clients attached to the IBMI can access. In non-geek this means “it’s a way of using IBMi data like it’s on a windows PC”

Whats good about the IFS?

I love the IFS and it’s a sometimes under-utilized function of the AS400… wait… iSeries… erm.. System-i? Ahh that’s right… it’s the IBMi operating system running on an IBM Power Server. This week. *cough*

You can store and access data from/to different file systems on your IBMI. IFS support is integral to the operating system and you don’t have to purchase any additional software to use it. All us IBMi developers know about the QSYS Library and if we want to look at it from the IFS we simply reference QSYS.LIB which is the IFS way of referring to a library. Files end in .FILE – its not rocket science ;)

Other standard IBMI IFS file systems include the following:

Root (/) contains stream files and directories that have the characteristics of the DOS and OS/2 operating systems. These files also support threadsafe APIs. Web server, Java objects and applications, HTML files, and personal data are commonly stored in a root subdirectory.

QOpenSys contains a hierarchical directory structure similar to a UNIX system. QOpenSys is compatible with UNIX-based operating system standards, such as POSIX and XPG, and has many of the same characteristics of the root file system with one significant difference. The QOpenSys file system is case-sensitive, meaning it can distinguish between upper- and lowercase names when performing file searches. This means QOpenSys can use duplicate names as long as there is some difference in each name’s upper- and lowercase spelling. You could have two objects in this file system, one named Midrange and the other named midrange, and QOpenSys would be able to tell the difference. This capability helps maintain compatibility with ported applications, but it can sometimes cause confusion when users are required to key in a file name with the correct case, such as when QOpenSys is used for Web serving.

QDLS supports IBMI folders and contains folders and document library objects. QDLS is the file system in which IBM stores all the old Client Access Shared Folders directories and files. In OfficeVision/400 documents or calendaring, this is the area where those objects are stored.

QFileSvr.400 provides transparent access to other file systems that reside on remote IBMIs. Unlike the other standard file systems, the characteristics of the QFileSvr.400 file system are determined by the characteristics of the file system being targeted on the remote IBMI.

QSYS.LIB is the System library.

QOPT has a structure similar to the root file system but is used to provide access to stream data stored on optical media, including direct-attached optical libraries or the CDROM drive on your IBMI.

QNTC doesn’t store any data directly on the IBMI but provides access to files and folders stored on Windows NT 4.0 servers running on standalone PC servers or on an Integrated Netfinity Server for IBMI card (formerly known as the Integrated PC Server, XPG or IPCS). Data is stored in stream files, and you need the TCP/IP Connectivity Utilities for IBMI product (part number 5769-TC1) installed to use QNTC support. See the OS/400- IBMI Integration with Windows NT Server V4R4 manual for more details on using QNTC.

There are also two other standard file systems that do not appear directly beneath the root of the OpsNav Integrated File System tree:

User-defined File System (UDFS) resides directly in an IBMI Auxiliary Storage Pool (ASP), whereas files and folders in other file systems reside in the system ASP. For more information about creating and manipulating a UDFS, see IBM’s OS/400 Network File System Support V4R4 manual.

Network File System (NFS) is a file system that allows you to share files with other servers running the NFS protocol.

In contrast, two nonstandard file systems are also listed in your OpsNav Integrated File System subtree—QLANSrv and QNetWare—but you need to purchase special IBM software products to use them. The QLANSrv file system provides access to the files and directories that are available to OS/400 through the OS/2 Warp Server for OS/400 licensed program. The QNetWare file system provides access to files and directories that are accessible from OS/400 when you are running Novell NetWare servers on the Integrated Netfinity Server for IBMI or on a standalone PC server. You can use QNetWare file system access only when you are running the Novell NetWare Enhanced Integration for IBMI product and have your Novell NetWare servers configured correctly.