Problem backup Exchange / problema com backup Exchange.

I am having a problem with netbackup in exchange backup.

I have one policy, with 20 bases, balanced on two servers,

18 bases always work and 2 return with error status 13.

occasionally it works all.

I found that after the error, the service 'Microsoft Exchange Writer Replica' hangs waiting for Completing

netbackup 7.6 (5220 appliance - linux)
exchange 2010
windows 2008 r2

09.18.2015 09:36:47 - Info nbjm (pid = 12818) starting backup job (jobid = 551671) for client dagsp, policy-DAG__dagsp__SP Exchange - TIMELY, schedule Full-Diario
09.18.2015 09:36:47 - Info nbjm (pid = 12818) Requesting MEDIA_SERVER_ONLY resources from RB for backup job (jobid = 551671, request id: {} ED78EFF4-5E01-11E5-8082-566DC13E44FD)
09.18.2015 09:36:47 - Requesting resource stu_disk_asap119pbkp
09.18.2015 09:36:47 - Requesting resource asap120pbkp.NBU_CLIENT.MAXJOBS.dagsp
09.18.2015 09:36:47 - Requesting resource asap120pbkp.NBU_POLICY.MAXJOBS.Exchange-DAG__dagsp__SP - SPOT
09.18.2015 09:36:47 - Requesting resource EXCHANGE_RESOLVER.asap120pbkp.Exchange-DAG__dagsp__SP - PONTUAL.dagsp
09.18.2015 09:36:47 - Granted resource asap120pbkp.NBU_CLIENT.MAXJOBS.dagsp
09.18.2015 09:36:47 - Granted resource asap120pbkp.NBU_POLICY.MAXJOBS.Exchange-DAG__dagsp__SP - SPOT
09.18.2015 09:36:47 - Granted resource EXCHANGE_RESOLVER.asap120pbkp.Exchange-DAG__dagsp__SP - PONTUAL.dagsp
09.18.2015 09:36:49 - estimated 338 198 365 kbytes needed
09.18.2015 09:36:49 - begin Parent Job
09.18.2015 09:36:50 - Info RUNCMD (pid = 2613) started
09.18.2015 09:36:50 - Info RUNCMD (pid = 2613) exiting with status: 0
Operation Status: 0
9/18/2015 9:36:50 - end Parent Job; elapsed time 0:00:01
Operation Status: 0
Operation Status: 0
09.18.2015 09:36:52 - started bpbrm process (pid = 2620)
09.18.2015 09:36:53 - Info bpbrm (pid = 2620) dagsp is the host to restore to
09.18.2015 09:36:53 - Info bpbrm (pid = 2620) File reading list for client
09.18.2015 09:36:55 - Info bpbrm (pid = 2620) client_pid = 29768
09.18.2015 09:36:56 - Info bpbrm (pid = 2620) from client dagsp: TRV - BPRESOLVER has executed on server (NSAP002PMBX)
09.18.2015 09:37:20 - Info bpbrm (pid = 2620) from client dagsp: TRV - Last backup attempt of database 'Microsoft Information Store: \ MBXSPVIPDB05-1' on server NSAP001PMBX failed. Will try to find another server in preferred server list.
09.18.2015 09:37:22 - Info bpresolver (pid = 29768) done. status: 0
09.18.2015 09:37:22 - Info bpresolver (pid = 29768) done. status: 0: the requested operation was successfully completed
Operation Status: 0
Operation Status: 0
Operation Status: 15
Operation Status: 0
09.18.2015 13:05:35 - Info RUNCMD (pid = 6293) started
09.18.2015 13:05:35 - Info RUNCMD (pid = 6293) exiting with status: 0
Operation Status: 0
Operation Status: 15
file close failed (15)