Yes, technically you can do the backup and restore on the client at the same time. But operationally as a Backup admin you should be aware the backup & restore is not for the same entity just to avoid any contention.
there could be a contention on backup device side. If you have tape device and the same tape medium is used both for backup and for restore, or when you have less tape drives than both backup and restore operation requires together, then you cannot do this simultaneously.
In other cases, especially with disk devices, simultaneous operations are not a problem.
Ok Please correct me if i am right or not.
If there is client A and i am restoring the data of client A to Client B when the backups are running for Client A.
Will the above work.
Yes, barring you using the same tapes, as someone else noted. Backup images in NBU are not directly related to each other, so the image you are creating with the new backup from Client A has no impact or direct correlation to the image you are reading from to restore to Client B.
just to add on this..
Restore can be done via a different media server if you allow the access from the client. So, if your backup is going through media server A and utilising 4 tape drives, you can have a restore job running via media server B and utilise another different tape drive.