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Controlling File Shares

File shares allow the directory files that are associated with to be available from network interfaces. File shares are often used to enable drive mapping. In the Windows world, shares are often defined to enable drive mapping for file and document sharing. The same can be implemented in the IFS on i5/OS. Now you may be wondering why you should be concerned with file shares if you don’t use them. Unless you know and track the file shares defined on your system, your system may be much more open than you think. Depending on the directory shared and the object authorities in place, every file—including every database file in your application libraries—may be accessible from Windows Explorer on every user’s PC. No, I’m not kidding.

If the root directory has been shared, the QSYS.LIB file system is shared. The QSYS.LIB file system is all of your libraries. Imagine what’s available to you—and every user on the system—if you map a drive to the root and the object authority of all libraries and files is at least *USE. All database files are now available through a Windows Explorer session.

Discovering the File Shares

To find the file shares defined on your system, open iSeries Navigator, go to “File Systems” and click “File Shares.” You’ll probably see at least two file shares listed. IBM ships the system with two file shares defined: Qibm, which is associated with the /QIBM path, and Qdirsrv, which is associated with the path /QIBM/ProdData/OS400/DirSrv. If you right-click on the share and choose “Properties,” you can see more details about the share, such as whether it’s a read/write share or a read-only share and how many connections are allowed for it.

Both directories and libraries can be shared. If you find the root directory or a key library has been shared and you don’t want the information available via the network, navigate from File Systems to Integrated File Systems to the directory or library being shared. You can easily spot it because an icon that looks like a hand will appear under the name. Right-click on the directory and choose Sharing>Stop Sharing.

Discovering Who’s Using the Share

Before you turn off a share, you may want to discover who, if anyone, is using it. To do this, open iSeries Navigator and go to Network>Servers and click “TCP/IP.” When the list of servers appears on the right, right-click “iSeries NetServer” and choose “Open.” Figure 1 shows an example of what’s displayed.

Clicking on either a share or session provides additional information in the right-hand pane. For example, when you click on the session in the left-hand pane, you’ll see the share it’s using.

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