When you said manually copied, did you mean you created a backup copy job ? 

Are you using the  same backup server which you used for first repository? 

same server. i add another LUN in VBR server and create new repo. in new repo i copy all data from my old repo and import in my new repo. 

Yes, incremental is possible if you map the backup files from the new location to the old backup job:

Step 8. Map Backup File - User Guide for VMware vSphere (veeam.com)

This plus after adding the new repo to the VBR server be sure to rescan it to import the backups in to the configuration database and then map them.

Let me try first in my R&D lab.

i think, for this job run successful last incremental backup must be error free.

As @Chris.Childerhose suggests, rescan is fundamental.

Add the new repo in your scale out repo, then evacuate date and seal the old repo

Another good suggestion for sure.  Using SOBR to move data just hope not ReFS.  

i try it in my lab. it’s work in windows repo. not sure about Linux repo.

First i add new repo, then copy all data from my old repo to new repo.

import new repo data from VBR, change the repo location from backup job. start job again. its working 

Thanks for the feedback.

Mapping is a cool feature.

That will work for all repo types :-)

Thanks for describing your solution!

Good to know: Currently this only works when you copied your backup-files upfront. If not, you would not be able to change target repository. Unless job did not start up to this moment. So if you need to change repository without coping data upfront, you can clone the job and change repo then. Of course, first backup will be a full.