Admin Alert: Hitting the Limits of the QNTC File System
May 5, 2004 Joe Hertvik
In a recent column, I discussed OS/400’s QNTC file system and its ability to treat Windows file systems as targets for ASCII and stream file operations. While QNTC is undeniably a good thing, I was incorrect in stating that QNTC lets you back up Windows data to an OS/400-based tape drive by using the Save Object (SAV) command. You can do this function, but only in one very specific OS/400 configuration.
The experience behind this statement occurred when a Windows network tape drive broke, leaving my shop without a reliable backup solution. “Great,” I thought, “I have an alternative: I can back up key network drives to my OS/400-based Ultrium tape drive or to a save file.” But this wasn’t possible. I learned my lesson when I tried to run the following SAV command to back up a Windows stand-alone server file to an OS/400-based save file.
SAV DEV('/qsys.lib/savlib.lib/network.file') + OBJ(('/QNTC/windows01/website/htmlfile.html'))
At which point, I received the following messages:
CPD3775 -- Cannot save or restore /QNTC/windows01/website/htmlfile.html. CPF3823 -- No objects saved or restored.
After some research, I found that it was not possible to save files to an OS/400 tape drive from an external network-connected Windows server. IBM told me that OS/400 does not support using the Save Object (SAV) and Restore Object (RST) commands to work with external network-connected Windows data. But IBM does allow you to use SAV and RST to work with data that resides on a Windows server running on an Integrated xSeries Server (IxS) for iSeries. And the possible reasons why are interesting.
According to “File Level Backup of Windows Server on iSeries Setup,” an IBM Software Technical Document, “the support for Windows file-level backup is not available to a network-connected server because the code comes packaged with AS/400 Integration for Windows Server.” This information is also available at the iSeries Information Center. AS/400 Integration for Windows Servers (renamed the iSeries Integration for Windows Servers in later releases) is a licensed product that IBM sells for supporting IxS-based servers with OS/400 resources. The frustrating thing is that this technical document provides complete instructions for using SAV and RST to back up Windows data, residing on IxS-based servers, to an OS/400-based tape drive, the exact same thing I was trying to do with my network-connected Windows server.
An IBM source corroborated this information by saying that the backup code would have to reside in the iSeries operating system in order to back up external Windows data to OS/400 tape drives, and that IBM probably will not provide this support in the future. It’s also possible that there may be some marketing concerns in only allowing OS/400 to back up /QNTC Windows data from IxS-connected servers (which IBM sells) and to deny backup to /QNTC-accessible Windows servers residing on machines that have no connection to Big Blue’s revenue stream.
To be fair to IBM, there is other code and capabilities in the iSeries Integration for Windows product that IBM probably won’t or can’t support on non-IBM servers, such as the capability to allocate OS/400-based tape drives directly to connected Windows servers. But it would sure be nice to be able to use SAV and RST on outside Windows servers, and it would also be nice if IBM decided to rethink these restrictions.
Whether it’s technological limitations or corporate politics or a combination of the two, the point is that it isn’t possible to use /QNTC, SAV, and RST to back up and restore Windows data from network-connected servers (but not IxS-connected servers). It’s a shame, though, because this capability would be a very nice feature that could help shops trying to consolidate network resources like tape drives.