After a new bulk tapes loaded into your library, you may realized that they could ended up to a mass order to your library. Like this:

$ mtx -f /dev/changer2 status | more
  Storage Changer /dev/changer2:6 Drives, 2636 Slots ( 16 Import/Export )
Data Transfer Element 0:Full (Storage Element 810 Loaded):VolumeTag = A02809
Data Transfer Element 1:Full (Storage Element 1349 Loaded):VolumeTag = A03753            
Data Transfer Element 2:Full (Storage Element 1351 Loaded):VolumeTag = A03348     
Data Transfer Element 3:Full (Storage Element 1485 Loaded):VolumeTag = A04514         
Data Transfer Element 4:Full (Storage Element 1754 Loaded):VolumeTag = A03484
Data Transfer Element 5:Full (Storage Element 2515 Loaded):VolumeTag = A03350
      Storage Element 1:Full :VolumeTag=A02000                          
      Storage Element 2:Full :VolumeTag=A02009                         
      Storage Element 3:Full :VolumeTag=A02002                          
      Storage Element 4:Full :VolumeTag=A02030                         
      Storage Element 5:Full :VolumeTag=A02100                         
      Storage Element 6:Full :VolumeTag=A02040                         
      Storage Element 7:Full :VolumeTag=A02006                          
      Storage Element 8:Full :VolumeTag=A02007                          
      Storage Element 9:Full :VolumeTag=A02008
...          

For applications, it's ok, since as long as they know where to find a particular tape, and where to put it back. However, sometime, if you want do some manual operations, such as eject a particular tape, or make a script to do bunch of stuff that you want. Keep the tape cartridge in order by volsor in line with slot number may be a good idea.

Here is just one example from IBM TS3500, more likely other high end libraries support similar feather, perhaps this can be a reference.

With ALMS(Advanced Library Management System) enabled, you can reshuffle library slots for tape cartridges without actually physically moving tapes. How?

Use mtx transfer command

mtx -f /dev/changer transfer <source slot> <target slot>

For example, if we want to move tape A02009( in above example) to slot 10, run command

mtx -f /dev/changer transfer 2 10

Of course you want empty the slot 10 before you move tape A02009 into it. A little scripting can help you move thousands of tapes easily. Again, not physical tape movement.

Other ways

You can always try to use library web interface to do that, but takes lots of clicks and time, here is how.

Choose Data catridges --> select frame, library, sort by volume serial --> search --> choose the tapes that you want to reassign --> unassign them 

Repeat this step to unassign all tape cartridges.

Then do similar steps to assgn these tape cartridges back to the library, remember to choose the volume order that you want. First assigned tape takes the first slot, and so on.

Also, you can try the library command line interface.

In this article, there some examples you can follow. IBM TS3500 command line interface examples