Standby database keeps falling behind.

Question

11.2.0.3 (Primary and Standby)
archive_lag_target                   integer 900
log_archive_config                   string
dg_config=(PROD,DR)
log_archive_dest                     string
log_archive_dest_1                   string
LOCATION=/oracle/archive/PROD VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=PROD
Hi there,
I have one primary with one standby datagaurd setup. The standby got 24 hours behind, so we shutdown the standby and re-synced on a storage level, but almost immediately it started lagging behind and two days later it's 20 hours behind again. Please help,
The archive logs are diffrent sizes as well :
-rw-r-----    1 oracle   dba      9608466944 Aug  1 02:18 prod-768088995-1-137005.ARC - prod
-rw-r-----    1 oracle   dba      9608854016 Aug  1 06:26 prod-768088995-1-137055.ARC - DR
It first fails then succeed applying the logs :
   THREAD#  SEQUENCE# APPLIED   COMPLETIO NEXT_TIME
         1     136558 NO        30/JUL/13 30/JUL/13
         1     136558 YES       30/JUL/13 30/JUL/13
         1     136559 YES       30/JUL/13 30/JUL/13
         1     136559 NO        30/JUL/13 30/JUL/13
         1     136560 NO        30/JUL/13 30/JUL/13
         1     136560 YES       30/JUL/13 30/JUL/13
         1     136561 NO        30/JUL/13 30/JUL/13
         1     136561 YES       30/JUL/13 30/JUL/13
         1     136562 NO        30/JUL/13 30/JUL/13
         1     136562 YES       30/JUL/13 30/JUL/13
         1     136563 NO        30/JUL/13 30/JUL/13
DR alert log :
Thu Aug 01 05:54:23 2013
FAL[server, ARC7]: FAL archive failed, see trace file.
ARCH: FAL archive failed. Archiver continuing
ORACLE Instance PROD - Archival Error. Archiver continuing.
Thu Aug 01 05:54:25 2013
Errors in file /oracle/diag/rdbms/rsaprod/PROD/trace/PROD_nsa2_13894020.trc:
ORA-19502: write error on file "", block number  (block size=)
LNS: Failed to archive log 3 thread 1 sequence 137134 (19502)
Thu Aug 01 05:54:37 2013
Archived Log entry 309536 added for thread 1 sequence 137134 ID 0xffffffff9138587b dest 1:
Thu Aug 01 05:54:53 2013
Thread 1 cannot allocate new log, sequence 137136
Thread 1 advanced to log sequence 137143 (LGWR switch)
  Current log# 1 seq# 137143 mem# 0: +DATA/prod/onlinelog/group_1.530.768090283
  Current log# 1 seq# 137143 mem# 1: +ARC/prod/onlinelog/group_1.263.768090301
Thu Aug 01 06:19:32 2013
Archived Log entry 309547 added for thread 1 sequence 137142 ID 0xffffffff9138587b dest 1:
Thu Aug 01 06:20:11 2013
minact-scn: got error during useg scan e:1555 usn:143
minact-scn: useg scan erroring out with error e:1555
Thu Aug 01 06:20:18 2013
LNS: Standby redo logfile selected for thread 1 sequence 137143 for destination LOG_ARCHIVE_DEST_2
Thu Aug 01 06:23:11 2013
minact-scn: got error during useg scan e:1555 usn:143

Answer 1

Hi,
Please provide the below.
1. show parameter log_archive_dest_2               --     From Primary
2. show parameter log_archive_dest_state_2      --     From Primary
3. select process, sequence#, status from v$managed_standby;          --     From standby
4.
SQL> alter session set NLS_DATE_FORMAT='DD-MON-YYYY HH24:MI:SS';               --     From Primary
Session altered.
SQL> select ERROR_CODE,TIMESTAMP,MESSAGE from V$DATAGUARD_STATUS where DEST_ID=2;          --     From Primary
Thank you!!