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* vpp: Enhanced memory and buffer configuration documentation - Added physmem configuration section with practical examples and troubleshooting - Clarified relationship between physmem and buffer allocation with cross-references - Improved VPP logging documentation with detailed log location descriptions - Fixed formatting issues in system configuration * vpp: Added CGNAT memory requirements Expanded CGNAT settings page with information about: - Memory requirements - Hardcoded simultaneous sessions limit * vpp: Added troubleshooting page Added page with basic steps for troubleshooting: - Capturing packets (PCAP) - Tracing packets - Additional diagnostics information from VPP - Automatic collection of most details with Python script --------- Co-authored-by: Daniil Baturin <daniil@baturin.org>
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3.8 KiB
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87 lines
3.8 KiB
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:lastproofread: 2025-09-04
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.. _vpp_config_dataplane_memory:
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.. include:: /_include/need_improvement.txt
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########################
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VPP Memory Configuration
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########################
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VPP heavily relies on hugepages for its memory management. Hugepages are larger memory pages that reduce the overhead of page management and improve performance for applications that require large amounts of memory, such as VPP.
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VPP supports both 2MB and 1GB hugepages, but the default and most commonly used size is 2MB. The choice of hugepage size can impact performance, with larger pages generally providing better performance for memory-intensive applications.
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Before configuring memory in VPP dataplane settings, you need to ensure that hugepages are enabled and properly configured on your system.
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.. seealso:: :ref:`Hugepages in VyOS Configuration for VPP <vpp_config_hugepages>`
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To configure memory settings for VPP, you can use the following commands in the VPP CLI:
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VPP uses a main heap as a central memory pool for FIB data structures entries allocations.
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Efficient memory management is crucial for VPP's performance, and the main heap plays a significant role in this.
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It can be configured using the following command:
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.. cfgcmd:: set vpp settings memory main-heap-page-size <size>
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Sets the main heap page size for VPP.
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.. cfgcmd:: set vpp settings memory main-heap-size <size>
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Sets the main heap size for VPP.
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.. _vpp_config_dataplane_physmem:
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Physical Memory Configuration
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=============================
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VPP uses physical memory for packet buffers and interface operations. The ``physmem`` setting controls how much memory VPP can allocate for these operations.
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.. cfgcmd:: set vpp settings physmem max-size <size>
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Sets the maximum amount of physical memory VPP can use for packet processing and interface buffers.
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**Default**: 16GB (usually sufficient for most deployments)
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You may need to modify the value for high-throughput environments with many interfaces, large packet buffers, or very high packet rates or memory-constrained systems where you need to limit VPP's memory usage.
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**Physmem Independent of main heap size** - physmem is for packet buffers, main heap is for routing tables.
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.. seealso::
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- :ref:`Hugepages in VyOS Configuration for VPP <vpp_config_hugepages>`
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- :ref:`VPP Buffer Configuration <vpp_config_dataplane_buffers>` - for controlling buffer allocation within physmem
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Common configurations
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---------------------
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.. code-block:: none
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# Reduce for memory-constrained systems
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set vpp settings physmem max-size 4G
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# Increase for high-throughput environments
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set vpp settings physmem max-size 32G
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Potential Issues and Troubleshooting
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====================================
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Improper configuration of main heap size can lead to performance degradation or even system instability. If VPP runs out of memory in the main heap, it may crash or exhibit erratic behavior. Symptoms you may observe include:
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- Increased latency or packet loss
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- Crashes or restarts of VPP processes, especially during routing table populating (e.g., BGP session establishment)
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- Error messages related to memory allocation failures
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You need to tune the main heap size based on expected FIB entries. Pay attention - same amount of routes with a single next-hop and with multiple next-hops will consume different amounts of memory.
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For physmem, insufficient allocation can lead to packet drops, interface initialization failures, and overall degraded performance. Symptoms include:
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- Packet drops or failures to allocate buffers
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- Increased latency or jitter in packet processing
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- Crashes or restarts of VPP processes under heavy load
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You need to tune the physmem settings based on expected traffic patterns and interface usage. Monitor memory usage closely and adjust the configuration as needed to ensure optimal performance.
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