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Overview and Installation
Getting started with MemVerge Memory Machine requries 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.
Introduction to MemVerge Memory Machine
MemVerge Memory Machine (Memory Machine) enables applications to expand from volatile memory (DRAM) into persistent memory (PMEM).
Transparent Memory Service
The Transparent Memory Service (TMS) intercepts Linux glibc.so function calls and reroutes them to the Distributed Persistent Memory Engine (DPME), which manages the MemVerge PMEM store.
Intercepted Memory Functions
The TMS library, mvmalloc.so, in Memory Machine supports a restricted set of glibc.so memory-management functions.

Overview and Installation
Getting started with MemVerge Memory Machine requries 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.
- Introduction to MemVerge Memory Machine
  MemVerge Memory Machine (Memory Machine) enables applications to expand from volatile memory (DRAM) into persistent memory (PMEM).
  - Introduction to PMEM
    Using volatile memory (DRAM) and persistent memory (PMEM) in combination enables applications to expand memory capacity relatively cheaply and to persist memory data objects, a capability that previously was only possible by writing to storage devices.
  - Transparent Memory Service
    The Transparent Memory Service (TMS) intercepts Linux glibc.so function calls and reroutes them to the Distributed Persistent Memory Engine (DPME), which manages the MemVerge PMEM store.
    - Intercepted Memory Functions
      The TMS library, mvmalloc.so, in Memory Machine supports a restricted set of glibc.so memory-management functions.
    - Configuring for Transparent Intercept
      Loading Transparent Memory Service (TMS) before glibc.so requires changing the LD_PRELOAD environment variable.
  - Differences Between Memory Machine Editions
    Memory Machine is available in two editions, Standard Edition for managing memory on individual hosts and Advanced Edition for managing clusters of hosts at the enterprise level.
  - The Distributed Persistent Memory Engine
    MemVerge Distributed Persistent Memory Engine (DPME) is at the heart of Memory Machine. DPME manages memory allocation to volatile memory (DRAM) and persistent memory (PMEM) for all applications run under Memory Machine.
  - The Control Path Service
    The Control Path Service (CPS) is a management service (as opposed to a data service) that manages aspects of Memory Machine not having to do with data.
  - Understanding Snapshots
    A snapshot is a static image of a running application's process tree. You can use Memory Machine ZeroIO Snapshot to almost instantly capture a snapshot, then later just as quickly restore the running process to the state captured in the snapshot.
- Getting Started with Memory Machine
  You run Memory Machine on a host equipped with one or more PMEM devices.
Using the Memory Machine Dashboard
You can view system resources and performance metrics, and create and restore snapshots in MemVerge Memory Machine using the Memory Machine Dashboard, a web UI application running on one of the installed hosts.
Using the Command Line Interface
You can administer and use MemVerge Memory Machine using the Command Line Interface (CLI) on any installed host.
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.

Intercepted Memory Functions

The TMS library, mvmalloc.so, in Memory Machine supports a restricted set of glibc.so memory-management functions.

Below is the list of glibc.so functions supported by TMS.

Function Group	glibc.so Function	Notes
Memory Allocation	`aligned_alloc()`
	`calloc()`
	`free()`
	`malloc()`
	`malloc_usable_size()`
	`memalign()`
	`posix_memalign()`
	`realloc()`
	`valloc()`
Memory-mapped file I/O	`mmap()`	Calls are rerouted to mvmalloc.so from glibc.so only if 1) MAP_PRIVATE and MAP_ANONYMOUS are set and 2) the data meet the size and flag restrictions in the configuration file specified by MVMALLOC_CONFIG. All other calls are forwarded directly to glibc.so.
	`mmap64()`	Same as `mmap()`.
	`madvise()`	Memory Machine supports only the MADV_DONTNEED and MADV_REMOVE advise values.
	`mprotect()`	Memory Machine cannot guarantee 4KB-aligned `mprotect()` requests. When a page under Memory Machine's management is changed to something other than read/write (PROT_READ \| PROT_WRITE), Memory Machine 1) converts that page to a private anonymous mapping, 2) permanently removes the page from MVMalloc’s internal data structures and maps, and 3) forwards the call to `glibc` for handling in DRAM.
	`mremap()`	The MREMAP_FIXED flag is not supported.
	`munmap()`	Portions of the region to be unmapped that are not managed by Memory Machine are presumed to have been allocated by glibc.so, so their unmap requests are also forwarded to glibc.so.
Execution	`execle()`	A subset of the execution functions are implemented to enable the `mvmalloc` library to preserve the environment when managing applications.
	`execpve()`
	`execve()`
I/O	`io_getevents()`	A subset of I/O functions are implemented to enable the mvmalloc library to get and send asynchronous I/O.
	`io_submit()`

Note: It is possible to capture either or both of the function groups (Memory Allocation and Memory-mapped I/O). Which groups are captured is controlled by a configuration file on startup. See Configuration Files.