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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.
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).
Calculating Process Count Limits

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).
  - Calculating Process Count Limits
  - Running an Application in Memory Machine
    To run an application with Memory Machine memory management, use the mm script supplied with Memory Machine.
  - Stopping an Application Instance
    Stop an application instance in whatever manner is recommended for the application you are running.
  - Configuring Application Memory
    Configure managed memory to optimize individual application instances. You can do this by setting the size of the DRAM tier and configuring Linux HugePages. You can make these adjustments "on the fly" while the application instance is running or configure Memory Machine to adust DRAM tier automatically as the application instance runs.
- 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.

Calculating Process Count Limits

About this task

The MemVerge Memory Allocation Service (MVMAS) on any host can support no more than about 21,800 PMem objects. Each machine process or snapshot of a machine process requires one PMem object. For example, if a running application instance uses three processes, and if there are four snapshots associated with the instance, then the application instance uses (3 + 4 * 3) = 15 PMem objects. When this MVMAS PMem limit is reached, then MVMAS can no longer create objects in PMem and must use DRAM for all new processes. This can cause drastic degradation of performance.

Procedure

If you know on average how many processes are required per application instance on a given data host, you can calculate the approximate workload at which this PMem object pool limit is reached:

supported app instances = 21,800 / ((snapshots + running instances) *
                        processes per instance)

Of course it is likely that the number of processes per instance varies widely. MemVerge recommends that you estimate process counts conservatively (err on the side of overestimating) and that you monitor host performance when counts of snapshot plus running instance get large (into the thousands, or even hundreds).