Backup completed with warning

Hi Folks,

i am facing below mentioned issue while perfoming the fulldata base backup. 

04/22/2016 15:05:25 - Error bpbrm (pid=22562) from client <HOSTNAME>-b: ERR - failure reading file: C:\Program Files\erst\iXSClient\var\lib\ixsclient.db.lck (WIN32 33: Unknown error)

04/22/2016 15:05:46 - Warning bpbrm (pid=22562) from client <HOSTNAME>-b: WRN - can't open file: C:\Program Files\Microsoft SQL Server\MSSQL\Data\master.mdf (WIN32 32: Unknown error)

04/22/2016 15:05:46 - Warning bpbrm (pid=22562) from client <HOSTNAME>-b: WRN - can't open file: C:\Program Files\Microsoft SQL Server\MSSQL\Data\mastlog.ldf (WIN32 32: Unknown error)

04/22/2016 15:05:46 - Warning bpbrm (pid=22562) from client <HOSTNAME>-b: WRN - can't open file: C:\Program Files\Microsoft SQL Server\MSSQL\Data\model.mdf (WIN32 32: Unknown error)

04/22/2016 15:05:46 - Warning bpbrm (pid=22562) from client <HOSTNAME>-b: WRN - can't open file: C:\Program Files\Microsoft SQL Server\MSSQL\Data\modellog.ldf (WIN32 32: Unknown error)

04/22/2016 15:05:46 - Warning bpbrm (pid=22562) from client <HOSTNAME>-b: WRN - can't open file: C:\Program Files\Microsoft SQL Server\MSSQL\Data\msdbdata.mdf (WIN32 32: Unknown error)

04/22/2016 15:05:46 - Warning bpbrm (pid=22562) from client <HOSTNAME>-b: WRN - can't open file: C:\Program Files\Microsoft SQL Server\MSSQL\Data\msdblog.ldf (WIN32 32: Unknown error)

04/22/2016 15:05:46 - Warning bpbrm (pid=22562) from client <HOSTNAME>-b: WRN - can't open file: C:\Program Files\Microsoft SQL Server\MSSQL\Data\northwnd.ldf (WIN32 32: Unknown error)

04/22/2016 15:05:46 - Warning bpbrm (pid=22562) from client <HOSTNAME>-b: WRN - can't open file: C:\Program Files\Microsoft SQL Server\MSSQL\Data\northwnd.mdf (WIN32 32: Unknown error)

04/22/2016 15:05:46 - Warning bpbrm (pid=22562) from client <HOSTNAME>-b: WRN - can't open file: C:\Program Files\Microsoft SQL Server\MSSQL\Data\pubs.mdf (WIN32 32: Unknown error)

04/22/2016 15:05:46 - Warning bpbrm (pid=22562) from client <HOSTNAME>-b: WRN - can't open file: C:\Program Files\Microsoft SQL Server\MSSQL\Data\pubs_log.ldf (WIN32 32: Unknown error)

04/22/2016 15:05:46 - Info bpbrm (pid=22562) from client <HOSTNAME>-b: TRV - last message being suppressed after 10 occurrences

04/22/2016 15:21:12 - Info bptm (pid=22563) waited for full buffer 30070 times, delayed 57009 times

04/22/2016 15:21:12 - Info bptm (pid=22563) EXITING with status 0 <----------

04/22/2016 15:21:12 - Info bpbrm (pid=22562) validating image for client <HOSTNAME>-b

04/22/2016 15:21:13 - Info bpbkar (pid=0) done. status: 1: the requested operation was partially successful

04/22/2016 15:21:13 - end writing; write time: 0:19:34

the requested operation was partially successful  (1)

kindly help to troubleshoot this issue.

Warm Regards

KUSH