NWSSTG not recognized after plain FTP-Restore

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The Integrated PC Servers (IPCS) cards for AS/400 machines use a file within the IFS for the guest OS to be used as Disk (container), just like VMDK files being used by various VMware products. This is also the case for newer OS/400 releases acting as Hypervisor for subordinate LPARs. These files are located in /qfpnwsstg.

Backup

A fast way to get the files off the system (backup, archival) is to just copy them via FTP, in binary mode, and while the assigned network server description is varied off.

Each storage space has two files in a subdirectory with the storage space's name:

  • QFPCONTROL
  • QFPCLTSTG1

It's not clear, nor publicly documented what kind of information is recorded in QFPCONTROL.

Restore

If you remove the storage spaces for some reason and just copy back the subdirectories with their files (also in binary mode), the spaces do not show up in wrknwsstg. This behavior is not the result of wrong access rights.

Apparently, storage spaces are registered elsewhere in the system.

If you used the sav command to put the storage spaces into a save file, the restore routine does what it takes to make the spaces known to the system. The drawback is that this is a rather slow and I/O intensive way. It also requires temporary space to copy the data into the save file.

Making them reappear

To make the system aware of the storage spaces being restored by FTP, use some means (e. g.) wrklnk '/qfpnwsstg/*' to rename the directories somehow.

Then create new, tiny "fake" storage spaces, but with the desired name:

CRTNWSSTG NWSSTG(NEW_C) NWSSIZE(5)

Next, move the contents of the renamed directories to the newly created storage space directories, in turn overwriting the newly created storage spaces.

The old storage spaces now show up again and can be assigned to a network server description.

See also