ZeroFS vs Azure Files Benchmarks
All tests ran on an Azure Standard D8ads v6 VM (8 vCPUs, 32 GiB memory) in the West Europe region. Results published August 2025.
Test Setup
- VM: Azure Standard D8ads v6, West Europe
- ZeroFS Storage: Azure Blob Storage (Hot tier)
- Azure Files Configuration: Hot tier, Standard performance
- Azure Files Mount: CIFS/SMB with cache=none (client-side caching disabled)
- Benchmark suite: github.com/Barre/ZeroFS/bench
- Operations per test: 10,000
Architecture Differences
ZeroFS: One userspace process serving Azure Blob Storage as a POSIX filesystem, mounted over 9P for these tests. No other infrastructure is involved.
Azure Files: Managed SMB/CIFS service with NFS support.
Performance at a Glance
Key Performance Differences
Benchmark Results
Synthetic Benchmarks
| Test | ZeroFS | Azure Files | Difference |
|---|---|---|---|
| Sequential Writes | |||
| Operations/sec | 988.18 | 28.32 | 34.9x faster |
| Mean latency | 1.01ms | 35.28ms | 34.9x slower |
| Success rate | 100% | 100% | - |
| Data Modifications | |||
| Operations/sec | 1,063.00 | 67.64 | 15.7x faster |
| Mean latency | 0.94ms | 14.78ms | 15.7x slower |
| Success rate | 100% | 100% | - |
| Single File Append | |||
| Operations/sec | 1,118.04 | 67.31 | 16.6x faster |
| Mean latency | 0.89ms | 14.85ms | 16.7x slower |
| Success rate | 100% | 100% | - |
| Empty Files | |||
| Operations/sec | 1,374.44 | 33.12 | 41.5x faster |
| Mean latency | 0.53ms | 30.17ms | 56.9x slower |
| Success rate | 100% | 100% | - |
| Empty Directories | |||
| Operations/sec | 1,597.71 | 41.08 | 38.9x faster |
| Mean latency | 0.62ms | 24.33ms | 39.2x slower |
| Success rate | 100% | 100% | - |
| Random Reads | |||
| Operations/sec | 1,389.42 | 327.18 | 4.2x faster |
| Mean latency | 0.72ms | 3.05ms | 4.2x slower |
| Success rate | 100% | 100% | - |
Real-World Operations
| Operation | ZeroFS | Azure Files | Notes |
|---|---|---|---|
| Git clone | 2.2s | 18.3s | ZeroFS repository |
| Cargo build | 2m 03s | Failed | Build artifacts corrupted |
| tar -xf (ZFS source) | 9.1s | 2m 41.6s | ZFS 2.3.3 release tarball |
Issues with Azure Files
Build Corruption
The cargo build failed on the Azure Files mount:
error: linking with `cc` failed: exit status: 1
= note: /media/bench/ZeroFS/zerofs/target/debug/deps/serde_derive-44a05269d948f943.serde_derive.f1ce333ee4d08087-cgu.12.rcgu.o:
file not recognized: file format not recognized
collect2: error: ld returned 1 exit status
Object files written during the build were corrupted; the linker could not use them.
Cost Analysis
Storage Cost Comparison
Based on Azure pricing in West Europe, as of August 2025:
Azure Files Pricing:
- Storage: $0.0271/GB-Month (Hot tier)
- LRS redundancy included
- Per-transaction charges apply
Azure Blob Storage Pricing (for ZeroFS):
- Storage: $0.0196/GB-Month (Hot tier)
- LRS redundancy included
- Per-transaction charges apply
Raw Storage Cost Comparison
| Storage Size | ZeroFS (Blob) Monthly | Azure Files Monthly | Cost Difference |
|---|---|---|---|
| 100 GB | $1.96 | $2.71 | 1.4x more expensive |
| 1 TB | $19.60 | $27.10 | 1.4x more expensive |
| 10 TB | $196.00 | $271.00 | 1.4x more expensive |
| 100 TB | $1,960.00 | $2,710.00 | 1.4x more expensive |
Annual Storage Cost Projection
| Storage Size | ZeroFS (Blob) Annual | Azure Files Annual | Annual Savings with ZeroFS |
|---|---|---|---|
| 100 GB | $23.52 | $32.52 | $9.00 |
| 1 TB | $235.20 | $325.20 | $90.00 |
| 10 TB | $2,352.00 | $3,252.00 | $900.00 |
| 100 TB | $23,520.00 | $32,520.00 | $9,000.00 |
Notes:
- The tables cover storage only. Both services also charge per transaction; those charges are not included.
- Both prices include LRS (Locally Redundant Storage).
Technical Details
Sequential Writes
Creates files in sequence. Tests metadata performance and write throughput.
ZeroFS: 10,000 files in 10.1 seconds
Azure Files: 10,000 files in 353.1 seconds (34.9x slower)
Data Modifications
Random writes to existing files. Tests consistency and caching.
ZeroFS: 10,000 operations in 9.4 seconds
Azure Files: 10,000 operations in 147.8 seconds (15.7x slower)
Single File Append
Appends to a single file. Tests lock contention and write ordering.
ZeroFS: 10,000 operations in 8.9 seconds
Azure Files: 10,000 operations in 148.6 seconds (16.6x slower)
Empty File Creation
Pure metadata operations without data writes.
ZeroFS: 10,000 files in 7.3 seconds
Azure Files: 10,000 files in 301.9 seconds (41.5x slower)
Empty Directory Creation
Tests directory metadata operations.
ZeroFS: 10,000 directories in 6.3 seconds
Azure Files: 10,000 directories in 243.4 seconds (38.9x slower)
Random Reads
Tests read performance from various file positions.
ZeroFS: 1,389.42 ops/sec
Azure Files: 327.18 ops/sec (4.2x slower)
Git Clone
Tests mixed read/write patterns with metadata operations.
ZeroFS: Completed in 2.2 seconds
Azure Files: Completed in 18.3 seconds (8.3x slower)
Compilation Workload
Rust compilation of ZeroFS codebase. Tests mixed read/write patterns and file consistency.
ZeroFS: 2 minutes 3 seconds (successful)
Azure Files: Failed - corrupted build artifacts
Archive Extraction
Extracting ZFS 2.3.3 source tarball. Tests sequential file creation with varying sizes.
ZeroFS: 9.1 seconds
Azure Files: 161.6 seconds (17.8x slower)
Summary
On this setup, ZeroFS completed the synthetic benchmarks 4.2x to 41.5x faster than Azure Files. The gap is widest in metadata operations: 24 to 35 ms mean latency on Azure Files against 0.5 to 1 ms on ZeroFS.
The Blob storage backing ZeroFS costs $0.0196/GB-month against $0.0271/GB-month for Azure Files (Hot tier, West Europe, storage only). The cargo build failed on Azure Files in this configuration with corrupted build artifacts; the same build completed on ZeroFS in 2 minutes 3 seconds.