9 Troubleshooting Zero Downtime Migration
This section describes how to handle migration job failures.
For more information about troubleshooting Zero Downtime Migration and known issues in the current release, see the Zero Downtime Migration Release Notes.
Handling Migration Job Failures
If your migration job fails, the following logs can help you discover the issue.
Migration Job Output Logs
If your migration job encounters an error, refer to the migration job output logs, Zero Downtime Migration service logs, and server-specific operational phase logs present at the respective source or target database servers.
If the migration job encounters an exception (that is, fails) then the logs can
provide some indication of the nature of the fault. The logs for the
migration procedures executed in the source and target environments are
stored on the servers in the respective source and target environments. The
Zero Downtime Migration command output location is provided to you when the
migration job is run with the ZDMCLI command
migrate database. You can also find the log file
location (Result file path) in the output of the
ZDMCLI command query job -jobid job-id.
Zero Downtime Migration Service Host Log
Determine which operational phase the migration job was in
at the time of failure, and whether the phase belongs to the source (phase
name contains SRC) or target (phase name contains
TGT) . Check the Zero Downtime Migration service
host log at $ZDM_BASE/crsdata/zdm_service_host/rhp/zdmserver.log.0,
and access the respective source or target server to check the log
associated with the operational phase in
$ORACLE_BASE/zdm/zdm_db_unique_name_job-id/zdm/log.
If the Zero Downtime Migration service does not start, then check the Zero Downtime
Migration service logs for process start-up errors to determine the cause of
the error reported. The Zero Downtime Migration service log can be found at
$ZDM_BASE/crsdata/zdm_service_host/rhp/zdmserver.log.0.
Data Pump Log
For logical migration jobs on co-managed target databases, refer to
the Data Pump log in the specified DATA_PUMP_DIR. For
Autonomous Database targets, the Data Pump logs are uploaded to a data
bucket specified with DATAPUMPSETTINGS_DATABUCKET_* in the
response file. If the data bucket is not specified, then you will need to
upload the dump from Autonomous Database to Object Storage to access it. See
How To View Import Log
Generated For ADW/ATP (Doc ID 2448060.1)
If a migration job fails, you can fix the cause of the failure and then re-run the job while monitoring the logs for progress.