Recover Old Tapes written by no longer existing Networker server

You can use the scanner command to recover data of old tapes. You would however need to create the client instances with the original hostid to restore the data off it. 

The below command will generate only the media and ssid information.

//Load the tape without mount
nsrmm -nlv -S slot -f drive

//Scanner command to generate only saveset information, this is faster
scanner -m drive_name

//Scanner command to generate saveset and index information, this is slower
scanner -i drive_name

In general, I support crazyrow's statement but I want to add some comments:

 - AFAIR, scanner will tell you about the client's hostid so you can easily recreate them.

 - Do not forget that you need to add an entry in the hosts file to resolve these names in case they do not exist or conflict with other IPs. IF NW will not be able to resolve the name, it will not (re-)create a client.

 - May I suggest that you add more verbosity to the command 'scanner -v ...' . This way you receive more information which might be helpful. And you receive a kind of 'process feedback'.

 - You may want to redirect the output to a file so that you can easily search for information later.

 - Watch the block size (scanner will report it). You might need to adjust it later.

 - 'scanner -i' will not necessarily take longer than 'scanner -m'

      - with both methods, the whole tape has to be read. This in general takes the same time.

      - many of small files will repopulate the CFI which might cause the tape to reposition. This will extend the duration of the process a bit, for sure.

           It is up to you whether you want to 'save time' using 'scanner -v -m ...' but if you want to repeat the whole process with 'scanner -v -i ...' later again. However, at this point in time you have the save set information already so you may now apply 'scanner -v -i ...' to a single save set.

If the tapes are much older, I hope you still have compatible hardware and drivers somewhere.