Home
Using the Command Line Interface
You can administer and use MemVerge Memory Machine using the Command Line Interface (CLI) on any installed host.
Using Snapshots in the Memory Machine CLI
Use the mvmcli snapshot command from the CLI on a Memory Machine host to capture the state of a running process, then later restore the running process to the captured state.
Using Snapshots in Memory Machine
Capturing a snapshot is almost instantaneous, requiring only that a small amount of metadata be saved to a storage device.
Restoring Snapshot Images
Restore a snapshot of an application image with the mvmcli snapshot restore command.
Restoring a TTY Session
Restore a TTY-connected application instance on the command line, optionally using tmux to redirect the TTY session.

Overview and Installation
Getting started with MemVerge Memory Machine requires that you understand some background information about how persistent memory works. 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 Interface
You can administer and use MemVerge Memory Machine using the Command Line Interface (CLI) on any installed host.
- MemVerge Memory Machine Administration
  MemVerge Memory Machine can be installed and run using CLI commands.
- Using the M3C Command Line 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).
- Using Snapshots in the Memory Machine CLI
  Use the mvmcli snapshot command from the CLI on a Memory Machine host to capture the state of a running process, then later restore the running process to the captured state.
  - Using Snapshots in Memory Machine
    Capturing a snapshot is almost instantaneous, requiring only that a small amount of metadata be saved to a storage device.
    - Preparing a System for Snapshots
      Snapshots can be captured on a host on which Memory Machine is properly configured and the data service is running.
    - Snapshot Dependencies
    - Capturing a Snapshot with CLI
      Capture snapshots of a running application using the mvmcli snapshot create command.
    - Listing Snapshots
      List snapshots using the mvmcli snapshot list command.
    - Restoring Snapshot Images
      Restore a snapshot of an application image with the mvmcli snapshot restore command.
      - Restoring a TTY Session
        Restore a TTY-connected application instance on the command line, optionally using tmux to redirect the TTY session.
      - Redirecting Files on Clone or Restore
        When restoring a snapshot, redirect file access to a new file or a copy of a file with the -e|--redirect or -E|--redirect-copy option, respectively.
    - Persisting a Snapshot
      You can make a snapshot persistent by forcing the snapshot data into PMem. This is called flushing the snapshot.
    - Removing Snapshots
      Remove snapshots with the mvmcli snapshot rm command.
    - Copying Snapshots
      You can export and import snapshots – copy them to conventional storage and back into PMem. You can also clone an instance, creating an exact duplicate that can be run concurrently with the original process. See oxy_ex-3/topics/t_mvmm_cloning_an_instance.html. Finally, you can replicate a snapshot – copy it from PMem on one host directly into PMem on another host. See oxy_ex-3/topics/c_mvmm_snapshot_replication.html.
- Troubleshooting
- Preparing Intel® Optane™ Persistent Memory PMem
  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.
All Documentation
Links to all technical documentation for MemVerge Memory Machine including previous releases.

Restoring a TTY Session

Restore a TTY-connected application instance on the command line, optionally using tmux to redirect the TTY session.

Before you begin

Install tmux version 1.8 or higher. The tmux utility must be in the execution path on the data host where you restore the session.

Note: Memory Machine automatically logs tmux sessions to a file. The log file path is /var/log/memverge/snapshot label_tmux_tmux session name_timestamp.log. You can use the option --tmux-log to change the log file path. Logging the tmux session saves it in cases where an application instance restored from a snapshot terminates, closing and destroying the tmux session.

Capture a snapshot of an application with an active command-line session, for example a Redis client console. See Capturing a Snapshot with CLI.

About this task

If you restore a snapshot of a process with an attached TTY session, the session opens on your current command line and blocks further shell input. To restore the TTY session to a different output (and have the current shell return), use the --tmux-session option when restoring.

Procedure

Restore the session. Assign a tmux session name with the --tmux-session option and, if you want, the tmux socket with the --tmux-socket option. For example:
```
$ mvmcli snapshot restore -l rediscli_511fc478 --tmux-session rc1 --tmux-socket /tmp/tmux-1022/my_tmux_socket
```
When using the --tmux-socket option, you must give the full pathname to the socket. For example: /tmp/tmux-1022/my_tmux_socket.

Each tmux socket is attached to a different tmux server. You can open additional tmux sessions and attach restored snapshots if, for example, you need different tmux options for different applications.

If you don't need different tmux configurations, you can ignore the --tmux-socket option and simply use the default in all instances.
Optional: List tmux sessions on the host with the tmux list-sessions command. For example:
```
$ tmux list-sessions
rc1: 1 windows (created Wed Sep 15 21:14:42 2021) [80x24]
```
Connect to the session using the tmux a command:
```
$ tmux attach -t session_name
```
where session_name is the name you supplied to the tmux-session option. For example:
```
$ tmux attach -t rc1
[rc1] 0:mvsnap*    "testdemo" 21:23 15-Sep-21
```
Important: You must have permission to access the tmux socket file path. We recommend that you log in as (or su to) the owner of the socket file path before connecting to the session.