Networker Oracle backup of cluster failing

Hi,

I have a Redhat cluster running Oracle in an active-passive setup.

A client has been setup with the cluster IP. The backup starts and runs for the archive logs , but when it gets to the data files , it fails and gives below error.

channel CH4: starting piece 1 at 13-MAR-20
RMAN-03009: failure of backup command on CH1 channel at 03/13/2020 18:59:30
RMAN-10038: database session for channel CH1 terminated unexpectedly
channel CH1 disabled, job failed on it will be run on another channel
RMAN-03009: failure of backup command on CH2 channel at 03/13/2020 18:59:30
RMAN-10038: database session for channel CH2 terminated unexpectedly
channel CH2 disabled, job failed on it will be run on another channel
RMAN-03009: failure of backup command on CH3 channel at 03/13/2020 18:59:30
RMAN-10038: database session for channel CH3 terminated unexpectedly
channel CH3 disabled, job failed on it will be run on another channel
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of backup plus archivelog command at 03/13/2020 18:59:30
RMAN-10038: database session for channel CH4 terminated unexpectedly.

What could be the cause of that.