If the Memory Tuning feature is enabled during setup, the setup algorithm determines the maximum Java Virtual Machine (JVM) heap size based on the total amount of available system memory. Otherwise, the server allocates a maximum JVM heap of 384 MB.
Directory Server also allows you to specify the maximum heap size during the setup process. For more information, see JVM Properties for Server and Command-Line Tools.
To enable Memory Tuning during the setup process:
- Select the feature in interactive command-line mode.
- Add the --jvmTuningParameter option using the setup tool in non-interactive command-line mode.
- Regenerate the Java properties file with bin/dsjavaproperties and the --jvmTuningParameter options.
If Memory Tuning is selected, the server allocates the maximum JVM heap depending on the total system memory. The following table displays the automatically allocated maximum JVM heap memory based on available system memory.
Allocated Max JVM Memory if Tuning is Enabled Available Memory Allocated JVM Memory
16 GB or more using a 64-bit JVM
The maximum JVM heap size is set to 70% of total system memory. If the maximum JVM heap size is less than or equal to 128GB of memory, which should be the case for systems with up to 160 GB of memory, then the initial heap size is set to equal the maximum heap size.
6 GB‒16 GB using a 64-bit JVM
Total system memory - 4 GB
4 GB–6 GB using a 64-bit JVM
2 GB–4 GB
1 GB–2 GB