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Configuring Zing Memory with ZST

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After ZST is installed you can configure Zing memory allocation. Zing requires a portion of host system memory to be set aside and managed independently from Linux. The system-config-zing-memory wizard assists with this.

The system-config-zing-memory creates or replaces any existing version of the pmem.conf file. Running the system-config-zing-memory wizard is required for first time installations.

This section describes creating a default configuration. To customize your Zing memory configuration, see Modifying Zing Memory Configuration.

With ZST 5.20.x you still should run system-config-zing-memory after installation as otherwise different default settings compared to ZST 5.19 and earlier will be applied.

  1. Complete the steps in Install Zing System Tools.

  2. Configure Zing memory management using the system-config-zing-memory command. Zing requires a portion of host system memory to be set aside and managed independently from Linux.

    Use the system-config-zing-memory wizard for initial configuration.

    From the command line, type:


    The system responds:

    Welcome to the Zing memory configuration wizard by Azul Systems. This wizard sets up the Zing memory configuration file /etc/zing/pmem.conf.0 and initializes System Zing memory. Read the man pages for zing, zing-zst, and zing-pmem-conf for more information about this configuration file.) Use of System Zing Memory by Java processes running on the Zing VM requires you to configure memory in advance. This is analogous to reservation of memory for Linux hugepages, although System Zing Memory pages are not interchangeable with hugepages. For most environments running Java applications on the Zing VM, Azul recommends configuring your system with 25% System Linux Memory and 75% System Zing Memory. Choose yes to accept this default, or no to enter the wizard expert flow. ** accept default configuration ** (y)es or (n)o [default 'y']: y
  3. Accept default configuration settings. At the prompt, type: y.

    The system response lists the zing services that are started or restarted and memory configuration information.

    For example:

    zing-memory: INFO: Restarting... zing-memory: INFO: Stopping... zing-memory: INFO: stop successful zing-memory: INFO: Starting... Info: Zing Memory reserved using reserve-at-config policy. Info: azulPmemPages: 54454. INFO: az_pmem_reserve_pages (num2mPages 54454) succeeded INFO: az_pmem_fund_transfer (to 7, from 0, bytes 114198315008) succeeded INFO: az_pmem_fund_transfer (to 1, from 7, bytes 5708447744) succeeded INFO: az_pmem_fund_transfer (to 3, from 7, bytes 5708447744) succeeded INFO: az_pmem_fund_transfer (to 0, from 7, bytes 102781419520) succeeded Info: You can now run Java processes up to -Xmx98020m or -Xmx95g. Info: Azul pmem initialized successfully. zing-memory: INFO: start successful zing-memory: INFO: restart successful

You have completed ZST installation. If you do not want to use the default settings, you can modify Zing memory usage. Configuration using the system-config-zing-memory command might fail, if ZST is unable to allocate the requested memory. The solution is to start ZST immediately after a fresh system reboot (see ZST Fails to Allocate Requested Memory for more information).