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Disk I/O Stress

Storage & Controller Performance Testing

Overview

The Disk I/O Stress module is designed to push your storage subsystem to its limits. It repeatedly creates, writes large alternating data patterns to, and then immediately deletes files to generate sustained, high-intensity disk input/output operations. This process stresses the disk drive, storage controller, and data buses.

Operations

Alternating Pattern Writes

This operation involves writing large files (2GB per cycle) using four distinct byte patterns (0xAA, 0x55, 0xFF, 0x00). This alternating data stream is designed to stress the disk's internal cache and wear-leveling algorithms, preventing predictable compression or optimization.

; Write 2GB with alternating buffer patterns mov r13, 8192 ; 8192 * 4 buffers * 64KB = 2GB per cycle ; Write buffer1 (0xAA pattern) mov rax, 1 mov rdi, r12 lea rsi, [rel buffer1] mov rdx, 65536 syscall

Rapid File Creation & Deletion

To maximize I/O stress and metadata operations, the module continuously creates new files, performs the large data writes, and then immediately deletes them. This cycle is repeated multiple times (8 cycles for 16GB total I/O), ensuring constant interaction with the file system and underlying storage hardware.

; sys_open - create new file each cycle for more I/O stress mov rax, 2 mov rdi, r15 mov rsi, 0x241 ; O_WRONLY | O_CREAT | O_TRUNC mov rdx, 0644o syscall ; sys_unlink - Immediately delete file to keep disk usage low mov rax, 87 mov rdi, r15 syscall

Hardware Stress Targets

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Disk Drive / SSD

Sustained large writes and metadata operations stress the physical platters/NAND, read/write heads, and internal controllers of the storage device.

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Storage Controller & Bus

High data throughput and constant command queues push the limits of SATA/NVMe controllers and the PCIe bus.

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File System & OS Cache

The rapid creation and deletion of files, coupled with alternating data patterns, challenges the operating system's file system and I/O caching mechanisms.

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System Thermals

Intensive I/O operations can increase the temperature of storage devices and surrounding components, testing system cooling.

Performance Characteristics

I/O Profile

16GB Total I/O (Default)
Write-Heavy Operation Type
Mixed Sequential/Random Access
High IOPS & Throughput

Technical Implementation

Optimization Resistance Features:

  • Alternating buffer patterns prevent data compression/deduplication
  • Rapid file creation/deletion stresses metadata and file system overhead
  • Large, fixed-size writes challenge disk internal caches
  • Direct system calls bypass higher-level OS optimizations

Assembly Optimizations:

  • Direct `sys_open`, `sys_write`, `sys_close`, `sys_unlink` calls
  • Large 64KB buffer writes for efficiency
  • Looping mechanisms for sustained I/O
  • Minimal overhead between I/O operations
⚠️ Performance & Drive Impact

This module will generate extremely high disk I/O. Extended execution, especially on SSDs, may contribute to drive wear (reduced lifespan) due to intensive write cycles. Ensure adequate system cooling and backup critical data before running intensive tests.

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