# 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.

---

# NVMe Local Storage Benchmark - Comparison Analysis

**Date:** 2026-01-19  
**Storage Class:** local-nvme-retain  
**Storage Backend:** Local NVMe SSD  
**Test Environment:** OpenShift Container Platform (OCP)  
**Tool:** fio (Flexible I/O Tester)

## Executive Summary

Local NVMe storage dramatically outperforms network-attached NFS storage, delivering **30-85x** higher throughput for sequential operations. Sequential read performance reaches **6845 MiB/s**, while sequential write achieves **2109 MiB/s** - compared to NFS's 80 MiB/s and 70 MiB/s respectively.

## NVMe Benchmark Results

### Sequential I/O (1M block size)

#### Sequential Write
- **Throughput:** 2109 MiB/s (2211 MB/s)
- **IOPS:** 2108
- **Test Duration:** 31 seconds
- **Data Written:** 64.1 GiB
- **Performance vs NFS:** **30x faster**

**Latency Distribution:**
- Median: 51 µs
- 95th percentile: 79 µs
- 99th percentile: 5.6 ms

#### Sequential Read
- **Throughput:** 6845 MiB/s (7177 MB/s)
- **IOPS:** 6844
- **Test Duration:** 20 seconds
- **Data Read:** 134 GiB
- **Performance vs NFS:** **85x faster**

**Latency Distribution:**
- Median: 50 µs
- 95th percentile: 816 µs
- 99th percentile: 840 µs

### Random I/O (4K block size)

#### Random Write
- **Throughput:** 989 MiB/s (1037 MB/s)
- **IOPS:** 253k
- **Test Duration:** 20 seconds
- **Data Written:** 19.3 GiB

**Latency Distribution:**
- Median: 1.4 µs
- 95th percentile: 1.8 µs
- 99th percentile: 2.2 µs

#### Random Read
- **Throughput:** 1594 MiB/s (1672 MB/s)
- **IOPS:** 408k
- **Test Duration:** 20 seconds
- **Data Read:** 31.1 GiB

**Latency Distribution:**
- Median: 980 ns
- 95th percentile: 1.3 µs
- 99th percentile: 1.6 µs

### Synchronized Write Test

**Purpose:** Measure actual storage performance with fsync

- **Throughput:** 197 MiB/s (206 MB/s)
- **IOPS:** 196
- **fsync latency:** 4.9ms average
- **Performance vs NFS:** **3x faster** (197 vs 66 MiB/s)
- **Latency vs NFS:** **3x lower** (4.9ms vs 15ms)

The significantly lower fsync latency (4.9ms vs 15ms for NFS) demonstrates the advantage of local storage for durability-critical operations.

### Mixed Workload (70% read / 30% write, 4 concurrent jobs)

- **Read Throughput:** 294 MiB/s
- **Read IOPS:** 75.2k
- **Write Throughput:** 126 MiB/s
- **Write IOPS:** 32.4k

**Note:** Lower than random I/O tests due to contention from 4 concurrent jobs and mixed read/write operations.

## Performance Comparison: NFS vs NVMe

| Test Type | NFS (nfs-csi) | NVMe (local-nvme-retain) | Improvement Factor |
|-----------|---------------|---------------------------|-------------------|
| **Sequential Write** | 70 MiB/s | 2109 MiB/s | **30x** |
| **Sequential Read** | 81 MiB/s | 6845 MiB/s | **85x** |
| **Sync Write (fsync)** | 66 MiB/s | 197 MiB/s | **3x** |
| **Random Write 4K** | 1205 MiB/s* | 989 MiB/s | - |
| **Random Read 4K** | 1116 MiB/s* | 1594 MiB/s | **1.4x** |
| **Random Write IOPS** | 308k* | 253k | - |
| **Random Read IOPS** | 286k* | 408k | **1.4x** |
| **fsync Latency** | 13-15ms | 4.9ms | **3x lower** |

*Note: NFS random I/O results are heavily cached and don't represent actual NAS performance

## Key Insights

### 1. Sequential Performance Dominance

NVMe's sequential performance advantage is dramatic:
- **Write throughput:** 2109 MiB/s enables high-speed data ingestion
- **Read throughput:** 6845 MiB/s ideal for data analytics and streaming workloads
- **Latency:** Sub-millisecond latency for sequential operations

### 2. Realistic Random I/O Performance

Unlike NFS tests which show cached results, NVMe delivers:
- **True 4K random write:** 989 MiB/s (253k IOPS)
- **True 4K random read:** 1594 MiB/s (408k IOPS)
- **Consistent sub-microsecond latencies**

### 3. Durability Performance

For applications requiring data durability (fsync operations):
- **NVMe:** 197 MiB/s with 4.9ms fsync latency
- **NFS:** 66 MiB/s with 15ms fsync latency
- **Advantage:** 3x faster with 3x lower latency

This makes NVMe significantly better for databases and transactional workloads.

## Storage Class Selection Guide

### Use NVMe (local-nvme-retain) For:

1. **Database Workloads**
   - High IOPS requirements (>10k IOPS)
   - Low latency requirements (<1ms)
   - Transactional consistency (fsync-heavy)
   - Examples: PostgreSQL, MySQL, MongoDB, Cassandra

2. **High-Performance Computing**
   - Large sequential data processing
   - Analytics and data science workloads
   - Machine learning training data

3. **Application Cache Layers**
   - Redis, Memcached
   - Application-level caching
   - Session stores

4. **Build and CI/CD Systems**
   - Fast build artifacts storage
   - Container image layers
   - Temporary compilation outputs

### Use NFS (nfs-csi) For:

1. **Shared Storage Requirements**
   - Multiple pods accessing same data (ReadWriteMany)
   - Shared configuration files
   - Content management systems

2. **Long-Term Data Storage**
   - Application backups
   - Log archives
   - Media file storage (videos, images)

3. **Cost-Sensitive Workloads**
   - Lower priority applications
   - Development environments
   - Acceptable 65-80 MiB/s throughput

### Hybrid Approach (Recommended):

Implement a tiered storage strategy:

```
┌─────────────────────────────────────────┐
│ Tier 1: NVMe (Hot Data)                │
│ - Databases                             │
│ - Active application data               │
│ - High-IOPS workloads                   │
│ Performance: 2000-7000 MiB/s            │
└─────────────────────────────────────────┘
           ↓ Archive/Backup
┌─────────────────────────────────────────┐
│ Tier 2: NFS (Warm Data)                │
│ - Shared files                          │
│ - Application backups                   │
│ - Logs and archives                     │
│ Performance: 65-80 MiB/s                │
└─────────────────────────────────────────┘
           ↓ Long-term storage
┌─────────────────────────────────────────┐
│ Tier 3: Object Storage (Cold Data)     │
│ - Long-term archives                    │
│ - Compliance data                       │
│ - Infrequently accessed backups         │
└─────────────────────────────────────────┘
```

## Cost Considerations

### NVMe Local Storage:
- **Pros:** Exceptional performance, low latency, no network overhead
- **Cons:** Node-local (no pod mobility), limited capacity per node
- **Best for:** Performance-critical workloads where cost-per-IOPS is justified

### NFS Network Storage:
- **Pros:** Shared access, unlimited capacity, pod mobility across nodes
- **Cons:** Network-limited performance, higher latency
- **Best for:** Shared data, cost-sensitive workloads, large capacity needs

## Final Recommendations

1. **For New Database Deployments:**
   - Use NVMe (local-nvme-retain) for primary storage
   - Use NFS for backups and WAL archives
   - Expected 30x performance improvement over NFS-only approach

2. **For Existing NFS-Based Applications:**
   - Migrate performance-critical components to NVMe
   - Keep shared/archival data on NFS
   - Measure application-specific improvements

3. **For High-Throughput Applications:**
   - NVMe sequential read (6845 MiB/s) enables near-real-time data processing
   - Consider NVMe for any workload exceeding 100 MiB/s sustained throughput

4. **Network Upgrade Still Valuable:**
   - Even with NVMe available, upgrading to 10 Gbps networking benefits:
     - Faster pod-to-pod communication
     - Better NFS performance for shared data
     - Reduced network congestion

## Conclusion

Local NVMe storage provides transformational performance improvements over network-attached NFS storage, with 30-85x higher throughput for sequential operations and consistent sub-millisecond latencies. This makes NVMe the clear choice for performance-critical workloads including databases, analytics, and high-IOPS applications.

However, NFS remains essential for shared storage scenarios and cost-sensitive workloads where 65-80 MiB/s throughput is sufficient. The optimal strategy combines both: use NVMe for hot data requiring high performance, and NFS for shared access and archival needs.

The benchmark results validate that storage class selection should be workload-specific, with NVMe delivering exceptional value for performance-critical applications while NFS serves broader organizational needs for shared and persistent storage.