The Zerto Virtual Manager (ZVM) retains standard level log files according to the value set in the logging configuration file. By default, a maximum of 150 standard logging level log files with a size of 10 MiB (10485760 bytes) each are retained. Once 150 standard level log files have been created, the ZVM begins to remove the oldest log file as each new log file is created. The information contained in the logs can be lost if the logs are removed by the ZVM too quickly.


When working with Assurestor Support to troubleshoot an issue, it may be helpful to temporarily increase the number of ZVM log files that are retained. The time frame covered within the logs varies depending on the rate information is written to the log file by the ZVM. A busy environment with more than one paired site, and more than 100 VPGs, will retain a much shorter time frame of log information than a quieter environment with one paired site and less than 25 VPGs.


Follow the directions below to change the ZVM standard log file retention. The log files are saved to the Logs directory contained in the Zerto Virtual Replication installation directory. Open the oldest log file within this directory to determine the time frame currently covered. The time stamp written to the first log line entry within this file will determine the oldest point in time covered by the logs. Since the rate of information generated by the Zerto Virtual Manager will fluctuate, observing the time frame covered at multiple points during a day or week will provide a more accurate estimate of the time frame covered by the logs.

Caution: Before you increase the number of ZVM standard log level files retained, ensure that there is sufficient disk space available to accommodate the new log files. A single file consumes 10 MiB, so increasing the number of log files retained by 100 will use an additional 1 GiB.

Locate the configuration file

Browse to the Zerto Virtual Replication installation directory. The default install directory is: %PROGRAMFILES%\Zerto\Zerto Virtual Replication
Within this directory, locate the file named: NLog.config

Backup the configuration file

Before making changes to this file, create a backup copy in another directory.

Edit the configuration file

Open the file with a text editor and locate the following line: archiveFileName="${basedir}/logs/log.{#####}.csv"
Beneath this line, a 'maxArchiveFiles' value is defined. Edit the numeric value to increase the number of logs retained.
Do not remove the quotations or the closing XML tag from this line. Save your changes and close the text editor.

Caution: Zerto does not recommend decreasing the number of logs from the default settings, or changing any other values within the log configuration file. Changing other values within this file may cause issues with the ZVM logging function, and prevent the Zerto Diagnostic Application or Remote Log Collector from collecting logs when requested.

Verify the changes have been applied successfully

The changes will apply as soon as the configuration file is saved. If any unexpected problems occur, replace the NLog.config file with the backup copy.

Note: This procedure will not change the Zerto Virtual Replication Appliance (VRA) log retention settings. Please contact Assurestor Support for assistance with VRA log changes.

Affected Versions: