SBP_DAG backup getting failed

Hi All,

My DAG setup is as follows:

In DAG setup we have three (3) servers.

2 servers backup getting succeeded,  But one server getting failed from last week.

Networker setup:

Networker server : Version 7.6

Clients version : 8.1

NMM Version : 3.0

--- Unsuccessful Save Sets ---

* vb1wsbpexch01mp.sbp.ads:APPLICATIONS:\Microsoft Exchange 2010 aborted

_ID: 1474156836;

NSR_SAVE_FROM_SAVEGRP_NSRSNAP: Yes, Yes;

                  NSR_SERVER: lb1neteng1p;

  NSR_SNAP_DELETE_ON_CLEANUP: 1;

               NSR_SNAP_TYPE: vss;

             NSR_STRICT_SYNC: 0;

                      optype: conventional;

              snap_id_list_1: NetWorker Module for Microsoft Applications,

                              Microsoft Volume Shadow Copy Service;

              snap_sessionid: 1474156842;

NMM .. Starting Backup. This operation may take a long time depending on the size of the data requested.

102019:nsrsnap_vss_save:NMM .. The rollover failed with error 'Traditional save returned error. saverc :-1'.  Refer to the PowerSnap logs for more information.NMM .. Error backing up one or more of the file system savesets: NMM .. Operation unit failed with error Traditional save returned error. saverc :-1.

64038:nsrsnap_vss_save:NMM .. Error creating NetWorker backup of snapshot: NMM .. Operation unit failed with error Traditional save returned error. saverc :-1.

63372:nsrsnap_vss_save:NMM .. Registration of snapshot set failed -- NMM .. Operation unit failed with error Traditional save returned error. saverc :-1

77175:nsrsnap_vss_save:NMM ..  completed commit replica with status of false.

Microsoft DiskPart version 6.1.7601

Copyright (C) 1999-2008 Microsoft Corporation.

On computer: VB1WSBPEXCH02MP

Automatic mounting of new volumes disabled.

37959:nsrsnap_vss_save:An internal error occurred.

.

63335:nsrsnap_vss_save:NMM backup failed to complete successfully.

Internal error.

102333 1474177291 3 0 0 15024 7268 0 vb1wsbpexch02mp nsrsnap_vss_save NSR error 21 Exiting with failure. 0

rror. saverc :-1'.  Refer to the PowerSnap logs for more information.NMM .. Error backing up one or more of the file system

* vb1wsbpexch03mp.sbp.ads:APPLICATIONS:\Microsoft Exchange 2010 aborted