Data Domain: Enabling DD Boost API Logging - Precert Logs

Summary: This article explains how to enable the Data Domain Boost (DD Boost) plugin logging when troubleshooting issues related to Boost and BoostFS. This is called a precert log.

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Instructions

Note: The DD Boost plugin does not log detailed API activity by default. Enabling precert logging using the ddboost_precert.ini file allows for deeper diagnostics. Incorrect file placement, missing permissions, or misconfiguration can prevent log generation.

Reasons to Enable API-Level (precert) Logging:

  • DD Boost or BoostFS operations are failing or behaving unexpectedly.
  • Engineering or Support requests detailed API-level logs for analysis.
  • No logs are generated despite expected Boost activity.

General Notes:

  • Only enable precert logging when explicitly requested by Engineering or Support.
  • Monitor disk space closely; logs can grow rapidly.
  • Ensure correct permissions and file placement.
  • Remove the .ini file to disable logging.
  • BoostFS must be unmounted and remounted for changes to take effect.

File Locations by OS

Operating System ddboost_precert.ini Location ddboost_precert.log Location
Linux /ddboost_precert.ini /DDLog/ddboost_precert.log
Solaris /ddboost_precert.ini /DDLog/ddboost_precert.log
UNIX /ddboost_precert.ini /DDLog/ddboost_precert.log
Windows C:\ddboost_precert.ini C:\DDLog\ddboost_precert.log

For BOOST and BoostFS Versions Prior to 7.0

Create an empty file named ddboost_precert.ini at the appropriate location (see table above). This enables logging to the default path.

For BOOST and BoostFS Version 7.0 and later

Create a configured ddboost_precert.ini file with the following contents:

precert_enabled=true
num_log_files=4
log_file_size=512
log_file_name=ddboost_precert.log
log_file_dir=/DDLog
ddcl_logs_include=true
ddcl_logs_sev=4
  • This configuration creates four log files of 512MB each (2GB total).
  • Adjust num_log_files and log_file_size as required.
  • Logs can be redirected to a different location if disk space is limited.

Linux BOOSTFS Client Setup

  1. Create /DDLog directory:

mkdir /DDLog

chmod 777 /DDLog

  1. Create /ddboost_precert.ini with the configuration above.

 

  1. Ensure BoostFS is unmounted and remounted:

mount -o log-level=debug <mount_point>

 

Windows BOOSTFS Client Setup

  1. Create C:\ddboost_precert.ini with the following content:
precert_enabled=true
num_log_files=3
log_file_size=500
log_file_name=ddboost_precert.log
log_file_dir=C:\DDLog
ddcl_logs_include=true
ddcl_logs_sev=4
  1. Create C:\DDLog and assign full read/write permissions.
  2. Unmount and remount BoostFS with debug logging enabled.

Cleanup and Disabling Logging

  1. Delete the ddboost_precert.ini file.
  2. Delete the DDLog directory and its contents.
  3. Remount BoostFS to apply changes.
  4. Collect BoostFS logs from /opt/emc/boostfs/log.

Additional Information

Frequently Asked Questions (FAQ)

    Question: What is DD Boost Precert Logging? 
    Answer: DD Boost Precert Logging is a diagnostic logging feature that records DD Boost API transactions between a DD Boost client and the Data Domain system. It is commonly used for troubleshooting performance issues, failures, latency, and communication problems.

    Question: What does Precert Logging capture? 
    Answer: Precert logging captures DD Boost API activity including read operations, write operations, backup activity, restore activity, DD Boost library interactions, API call timing information, and client-side latency indicators. It provides detailed visibility into DD Boost API behavior for troubleshooting and performance analysis.

    Question: Why are no precert logs being generated? 
    Answer: Verify that the ddboost_precert.ini file exists, is located at the operating system root, the log directory exists, the log directory is writable, and a new backup or restore operation has started. Missing configuration, incorrect placement, permission issues, or lack of new DD Boost activity are the most common causes.

    Question: Does enabling precert logging immediately generate logs? 
    Answer:  No, log files are generated only when new DD Boost API requests are received. The configuration only enables logging capability.

    Question: Why doesn't my currently running backup generate precert logs? 
    Answer: Precert logging only captures API activity initiated after the configuration is detected. Existing backup or restore jobs continue without generating precert logs.

    Question: Do I need to restart my backup or restore job? 
    Answer: Yes, a new backup or restore job is required to generate precert logs.  If the job was already running when logging was enabled, start a new operation.

    Question: What is the most common reason precert logging does not work? 
    Answer:  Common causes include ddboost_precert.ini not being at the root level, being accidentally named ddboost_precert.ini.txt, a missing log directory, or insufficient permissions. Configuration and filesystem issues are the most frequent causes.

    Question: Where should the ddboost_precert.ini file be placed? 

    Linux: /ddboost_precert.ini. Windows: C:\ddboost_precert.ini.

    Answer: The file must reside in the operating system root directory.

    Question: Can the ddboost_precert.ini file be stored in another folder? 
    Answer: No, the file must be stored at the root. The DD Boost plugin only checks the operating system root directory.

    Question: How can I verify the file is not actually 

    ddboost_precert.ini.txt

    Open File Explorer, enable File Name Extensions, and verify the filename.
    Answer: Ensure the file is named 

    ddboost_precert.ini and not ddboost_precert.ini.txt.

    Question: Why is the DDLog directory empty after enabling logging?
    Answer: Run a new backup, restore, or DDPCONNCHK test to generate activity.  Possible causes include no new DD Boost activity, permission issues, or a configuration file that was not detected.

    Question: What is DDPCONNCHK and why is it useful? 
    Answer: DDPCONNCHK is a DD Boost connectivity validation tool. It can generate DD Boost API activity and quickly confirm that precert logging is working.

    Question: Can DDPCONNCHK be used to test my configuration?
    Answer:  Engineers frequently run DDPCONNCHK after enabling logging. Yes, it is a common way to verify logs are being generated before reproducing a problem.

    Question: Why are my precert logs growing so quickly?
    Answer:  Precert logging records every DD Boost API call. Large backup environments can generate significant log volume in a short time.

    Question: How much disk space should I allocate? A common recommendation is 

    num_log_files=3 and log_file_size=500.

    Answer: This provides approximately 1.5 GB of log storage before rotation occurs.

    Question: Can precert logs fill a filesystem? 
    Answer: Logging can consume significant disk space if not monitored. Yes, full filesystems can result in backup failures, outages, and service interruptions.

    Question: What is the purpose of num_log_files? 
    Answer: This parameter controls the number of rotated log files retained. For example, num_log_files=3 creates ddboost_precert.log, ddboost_precert.log.1, and ddboost_precert.log.2.

    Question: What is the purpose of log_file_size? 
    Answer: This parameter defines the maximum size of each log file in MB. For example, log_file_size=500 allows each file to grow to 500 MB before rotation.

    Question: What does ddcl_logs_include=true do?
    Answer:  It enables DD Boost Client Library logging information within the precert logs. The recommended setting is ddcl_logs_include=true.

    Question: What does ddcl_logs_sev=4 mean?
    Answer:  This parameter controls logging severity. Severity level 4 provides detailed troubleshooting and debugging information.

    Question: Do I need BoostFS debug logging in addition to precert logging? 
    Answer: Additional logging is not always required. For BoostFS-specific issues, enabling both often provides a more complete diagnostic picture.

    Question: For BoostFS, do I need to unmount and remount? 
    Answer: Unmounting and remounting reinitializes BoostFS activity. In many cases, yes, this helps initiate new DD Boost activity.

    Question: What is the correct BoostFS debug logging syntax?
    Answer:  The correct syntax is -o log-level=debug. Do not use --o log-level=debug because only a single dash is valid.

    Question: Why did remounting BoostFS suddenly make precert logs appear? 
    Answer: Remounting creates a new initialization cycle for BoostFS. Logging begins when new DD Boost API activity occurs and the plugin detects the configuration file.

    Question: Is restarting an application equivalent to remounting BoostFS? 
    Answer: Usually yes, examples include restarting RMAN, backup software, or running DDPCONNCHK. Any action that creates new DD Boost API activity can trigger logging.

    Question: Can RMAN generate precert logs without unmounting BoostFS? 
    Answer: Yes, starting a new RMAN operation is normally sufficient. RMAN can initiate new DD Boost API requests directly.

    Question: How do I disable precert logging?
    Answer:  Delete ddboost_precert.ini or rename it to ddboost_precert.ini.disabled.

    Question: Do I need to reboot the host after removing the ini file? 
    Answer: No, rebooting is not required. 

    Question: What permissions should be used on Linux? Example permissions include 

    mkdir /DDLog, chmod 777 /DDLog, and chmod 777 /ddboost_precert.ini.

    Answer: The DD Boost process must be able to read the configuration file and write to the log directory.

    Question: Where are BoostFS logs stored by default? 

    Linux: /opt/emc/boostfs/log. Windows: C:\BoostFS\Log.

    Answer: These locations are separate from DD Boost precert logs.

    Question: Are BoostFS logs and precert logs the same thing? 
    Answer: No, precert logs contain DD Boost API transactions, library communications, and I/O timing data. BoostFS logs contain mount activity, filesystem operations, and application events.

    Question: What logs should I provide to Support? 
    Answer: Providing all relevant logs helps accelerate troubleshooting. Depending on the issue, collect ddboost_precert.log, rotated precert logs, BoostFS logs, DDPCONNCHK output, application logs, and requested support bundles.

    Question: What should I do if logs still are not generated after following this KB? 
    Answer: Collect evidence such as the ddboost_precert.ini location, log directory listing, DDPCONNCHK output, BoostFS mount command, and permissions information. Submit the collected information to Dell Technical Support for further analysis.

    Affected Products

    Data Domain

    Products

    Data Domain
    Article Properties
    Article Number: 000020437
    Article Type: How To
    Last Modified: 28 Aug 2026
    Version:  10
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