SAP PERFORMENCE ISSUE DUE TO SAP BACKUP ?

Dear Experts,

We are taking Whole database online+redolog on tape drive (which is
directly connected to the server through with the fiber channel) backup
at generally 1 o'clock at daytime. It would take around 2 hours to
complete the backup.

Sometimes users start complaining that system got slow and they were
complaining about slow performance of the system, is there any impact of
the database backup on the performance of the system.

Please suggest , as this is very serious concern for us.

Regards

Rajat Jain