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Memory Machine Administration
MemVerge Memory Machine can be installed and run using CLI commands. Many administrative tasks can be performed using the Memory Machine Management Center web interface.
Troubleshooting
License Issues

Overview and Installation
Understanding how persistent memory works is helpful when getting started with MemVerge Memory Machine. You can then install Memory Machine on a server and begin monitoring memory usage and capturing application snapshots.
Using the Memory Machine Management Center
Memory Machine Management Center (M3C) is a web UI application available on the host that is running the Memory Machine Management Service. You can view system resources and performance metrics; create and restore snapshots; schedule jobs; and more in M3C.
Using the Command Line Tools
You can administer and use MemVerge Memory Machine using a Command Line Interface (CLI).
Memory Machine Administration
MemVerge Memory Machine can be installed and run using CLI commands. Many administrative tasks can be performed using the Memory Machine Management Center web interface.
- Upgrading Memory Machine
  To upgrade Memory Machine, run the Memory Machine Package File on each host using the --upgrade option.
- Uninstalling Memory Machine
- Upgrading Application Dependencies
  Upgrading dependency packages for snapshotted applications may render existing snapshots of that application unrestorable.
- Understanding the Memory Machine Database
  Memory Machine Memory Machine Management Center (M3C) uses a database to store information about preferences, statistics, and configurations. You must choose a database system for M3C to use.
- Understanding the Memory Machine Software License
  You must have a valid license to run Memory Machine. The license file is read at startup by the MemVerge Memory Allocation Service (MVMAS). Without a license, MVMAS defaults to running applications using only DRAM.
- Running Memory Machine Services
  Memory Machine data services must be running to enable PMem management, snapshot operations, and connection to the Memory Machine Management Center (M3C).
- Using the MemVerge Memory Allocation Service
  The MemVerge Memory Allocation Service (MVMAS), mvmallocd, is a service that maps programmatic memory to PMem. See oxy_ex-3/topics/a_mvmm_dpme_intro.html.
- Resetting a Host
  Reset a host by removing all snapshot and log data and initializing the DAX devices. This erases the host's PMem.
- Reporting Tiering Statistics
  Use the mvmcli command to view information about paging activity between PMem and the DRAM performance tier for an application.
- Viewing Logs
  Examine the Memory Machine log files to troubleshoot errors – for example, to determine why a license didn't load.
- Managing Application Memory
  To manage application memory with Memory Machine, you run the application on a data host in an environment with Transparent Memory Service (TMS) and MemVerge Memory Allocation Service (MVMAS).
- Troubleshooting
- Preparing Intel® Optane™ Persistent Memory
  Prepare PMem for use by configuring the Intel Optane Persistent Memory Direct Access (DAX) devices in AppDirect mode.
- Preparing to Run an Application
  Normally you run applications by using the mm wrapper script supplied with Memory Machine. See oxy_ex-3/topics/t_mvmm_running_an_application_with_mvmm.html. If you do not use the mm to run your application, you must set up the Memory Machine environment manually before running the application.
Working with Applications
MemVerge provides additional instructions for some popular applications supported by Memory Machine, either to assist with complex setup or to support additional functionality.

License Issues

Cannot Write to PMem

Memory Machine uses DRAM but not PMem, or reads but does not write to PMem.

Cause: Expired license

An expired license causes MVMAS to switch to read-only mode.

Remedy: Check and replace license

Procedure

Check the license in /etc/memverge/license.lic.
If the license is expired, purchase a new license and replace the license file. See Understanding the Memory Machine Software License.
Optional: Check the Memory Machine log file at /var/log/message.

The following warnings are associated with license expiration:

[ALERT] License is expired. DPME is in read-only mode.

Licenses is expired.

[ALERT] License will expire in X days.

License expiration is imminent. Notifications begin 7 days before expiration.

[ALERT] License in 7-day grace period

License has expired and is in the renewal grace period. Renew the license within X days.

[ALERT] License is invalid. DPME is in read-only mode. Please upload a valid license.

The license is corrupted or invalid for some other reason. Contact MemVerge support for a new license.

[ALERT] Unable to load license from path/to/license.

The file path given for the license file does not contain a readable file. Ensure that /etc/memverge/license.lic is a valid license file.

Cause: Licenses usage exceeded

A system that exceeds licensed memory usage continues to run, but uses only DRAM.

Remedy: Check and replace license

Procedure

Check the license in /etc/memverge/license.lic.
If the license capacity is less than the amount of PMem currently used by the system:
- Purchase a higher-capacity license and replace the license file. See Understanding the Memory Machine Software License.
- Reduce the memory footprint of the applications that are using PMem so that they run within the licensed amount.
Optional: Check the Memory Machine log file at /var/log/message.

The following warnings are associated with license capacity:

[ALERT] At 90% of licensed usage.

PMem usage is within 90% of allowed usage.

[ALERT] At 100% of licensed usage. Switching to DRAM soon.

PMem usage is at the licensed limit. Memory Machine is about to switch to using only DRAM for further operations.

[ALERT] Exceeded licensed usage. Using DRAM only.

PMem usage has exceeded the licensed limit. Memory Machine is using only DRAM.