NSX Edge datapath memory usage is over 85% on small form factor nodes.

Products

• VMware NSX

Issue/Introduction

• The NSX Manager UI displays an alarm: Edge Datapath mempool usage high alarm.
  
  syslog:
  <TIMESTAMP> datapathd <ID> stats tname="stats12" [ERROR] {"event_state":86,"event_external_reason":"Edge datapath memory usage is over 85%","event_src_comp_id":"<NODE_UUID>","event_sources":{"pool_name":"malloc_heap"}}  eventId="vmwNSXEdgeMpoolUsage"

• NSX Edge is deployed as Small form factor. In small form factor, NSX Edge node has only 4 GB.
  
  /proc/meminfo
MemTotal:        3658904 kB
MemFree:           74348 kB
MemAvailable:    1699124 kB
  
  NSX Edge VM System Requirements

Environment

VMware NSX 4.1

Cause

In NSX 4.1 and later, new features were introduced in datapath, which increased the baseline memory footprint of the datapath process.
Small form factor Edges allocate only 1GB of heap memory for the datapath. This allocation is often insufficient for production environments, especially if:

1. The node is processing significant traffic.
2. The **Tx/Rx ring sizes** have been increased above the default value of 2048.
3. Stateful services (Firewall, NAT, Load Balancing) are heavily utilized.

Small form factor nodes are intended primarily for Proof of Concept (POC) or lab environments and are not recommended for production workloads.
NSX Edge VM System Requirements

Resolution

Upgrade the Edge node to a Medium or larger form factor, which provides a significantly larger datapath heap (typically 4GB+ depending on the version and size).

Additional Information

NSX Edge VM System Requirements

KB 330516 Edge Datapath mempool usage high alarm

KB 383091 Resize NSX Edge Node