Add Claude NFS benchmark results

Comprehensive NFS performance analysis using nfs-csi storage class.
Tests included sequential I/O, random I/O, sync writes, and mixed workloads.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

claude-nfs-benchmark.md

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+# NFS Performance Benchmark - Claude Analysis
+
+**Date:** 2026-01-19  
+**Storage Class:** nfs-csi  
+**NFS Server:** 192.168.0.105:/nfs/NFS/ocp  
+**Test Environment:** OpenShift Container Platform (OCP)  
+**Tool:** fio (Flexible I/O Tester)
+
+## Executive Summary
+
+Performance testing of the NAS storage via nfs-csi storage class reveals actual throughput of **65-80 MiB/s** for sequential operations. This represents typical performance for 1 Gbps Ethernet NFS configurations.
+
+## Test Configuration
+
+### NFS Mount Options
+- **rsize/wsize:** 1048576 (1MB) - optimal for large sequential transfers
+- **Protocol options:** hard, noresvport
+- **Timeout:** 600 seconds
+- **Retrans:** 2
+
+### Test Constraints
+- CPU: 500m
+- Memory: 512Mi
+- Namespace: nfs-benchmark (ephemeral)
+- PVC Size: 5Gi
+
+## Benchmark Results
+
+### Sequential I/O (1M block size)
+
+#### Sequential Write
+- **Throughput:** 70.2 MiB/s (73.6 MB/s)
+- **IOPS:** 70
+- **Test Duration:** 31 seconds
+- **Data Written:** 2176 MiB
+
+**Latency Distribution:**
+- Median: 49 µs
+- 95th percentile: 75 µs
+- 99th percentile: 212 ms (indicating occasional network delays)
+
+#### Sequential Read
+- **Throughput:** 80.7 MiB/s (84.6 MB/s)
+- **IOPS:** 80
+- **Test Duration:** 20 seconds
+- **Data Read:** 1615 MiB
+
+**Latency Distribution:**
+- Median: 9 ms
+- 95th percentile: 15 ms
+- 99th percentile: 150 ms
+
+### Synchronized Write Test
+
+**Purpose:** Measure actual NAS performance without local caching
+
+- **Throughput:** 65.9 MiB/s (69.1 MB/s)
+- **IOPS:** 65
+- **fsync latency:** 13-15ms average
+
+This test provides the most realistic view of actual NAS write performance, as each write operation is synchronized to disk before returning.
+
+### Random I/O (4K block size, cached)
+
+**Note:** These results heavily leverage local page cache and do not represent actual NAS performance.
+
+#### Random Write
+- **Throughput:** 1205 MiB/s (cached)
+- **IOPS:** 308k (cached)
+
+#### Random Read
+- **Throughput:** 1116 MiB/s (cached)
+- **IOPS:** 286k (cached)
+
+### Mixed Workload (70% read / 30% write, 4 concurrent jobs)
+
+- **Read Throughput:** 426 MiB/s
+- **Read IOPS:** 109k
+- **Write Throughput:** 183 MiB/s
+- **Write IOPS:** 46.8k
+
+**Note:** High IOPS values indicate substantial local caching effects.
+
+## Analysis
+
+### Performance Characteristics
+
+1. **Actual NAS Bandwidth:** ~65-80 MiB/s
+   - Consistent across sequential read/write tests
+   - Synchronized writes confirm this range
+
+2. **Network Bottleneck Indicators:**
+   - Performance aligns with 1 Gbps Ethernet (theoretical max ~125 MiB/s)
+   - Protocol overhead and network latency account for 40-50% overhead
+   - fsync operations show 13-15ms latency, indicating network RTT
+
+3. **Caching Effects:**
+   - Random I/O tests show 10-15x higher throughput due to local page cache
+   - Not representative of actual NAS capabilities
+   - Useful for understanding application behavior with cached data
+
+### Bottleneck Analysis
+
+The ~70 MiB/s throughput is likely limited by:
+
+1. **Network Bandwidth** (Primary)
+   - 1 Gbps link = ~125 MiB/s theoretical maximum
+   - NFS protocol overhead reduces effective throughput to 55-60%
+   - Observed performance matches expected 1 Gbps NFS behavior
+
+2. **Network Latency**
+   - fsync showing 13-15ms indicates network + storage latency
+   - Each synchronous operation requires full round-trip
+
+3. **NAS Backend Storage** (Unknown)
+   - Current tests cannot isolate NAS disk performance
+   - Backend may be faster than network allows
+
+## Recommendations
+
+### Immediate Improvements
+
+1. **Upgrade to 10 Gbps Networking**
+   - Most cost-effective improvement
+   - Could provide 8-10x throughput increase
+   - Requires network infrastructure upgrade
+
+2. **Enable NFS Multichannel** (if supported)
+   - Use multiple network paths simultaneously
+   - Requires NFS 4.1+ with pNFS support
+
+### Workload Optimization
+
+1. **For Write-Heavy Workloads:**
+   - Consider async writes (with data safety trade-offs)
+   - Batch operations where possible
+   - Use larger block sizes (already optimized at 1MB)
+
+2. **For Read-Heavy Workloads:**
+   - Current performance is acceptable
+   - Application-level caching will help significantly
+   - Consider ReadOnlyMany volumes for shared data
+
+### Alternative Solutions
+
+1. **Local NVMe Storage** (for performance-critical workloads)
+   - Use local-nvme-retain storage class for high-IOPS workloads
+   - Reserve NFS for persistent data and backups
+
+2. **Tiered Storage Strategy**
+   - Hot data: Local NVMe
+   - Warm data: NFS
+   - Cold data: Object storage (e.g., MinIO)
+
+## Conclusion
+
+The NAS is performing as expected for a 1 Gbps NFS configuration, delivering consistent 65-80 MiB/s throughput. The primary limitation is network bandwidth, not NAS capability. Applications with streaming I/O patterns will benefit from the current configuration, while IOPS-intensive workloads should consider local storage options.
+
+For significant performance improvements, upgrading to 10 Gbps networking is the most practical path forward.
+
+---
+
+## Test Methodology
+
+All tests were conducted using:
+- Ephemeral namespace with automatic cleanup
+- Constrained resources (500m CPU, 512Mi memory)
+- fio version 3.6
+- Direct I/O where applicable to minimize caching effects
+
+Benchmark pod and resources were automatically cleaned up after testing, following ephemeral testing protocols.