When we examine traditional RAID 0 implementations, data striping across multiple drives is fundamental. However, certain storage controllers and modern filesystems implement RAID 0 configurations even with single drives. This creates an interesting technical scenario where the system maintains RAID 0 metadata structures and access patterns despite having no actual striping partners.

In single-drive RAID 0 configurations, the storage controller or software RAID layer still processes I/O requests using RAID 0 algorithms. Here's what happens at the technical level:

// Simplified RAID 0 request handling pseudocode
void handle_io_request(io_request *req) {
    if (num_disks == 1) {
        // Special case for single-drive RAID 0
        req->stripe_size = min(req->length, DEFAULT_STRIPE_SIZE);
        submit_to_disk(req->lba, req->data, req->length);
    } else {
        // Regular multi-disk striping
        handle_striped_request(req);
    }
}

The performance difference compared to JBOD comes from several factors:

• Queue depth optimization in RAID mode
• Different alignment and caching behaviors
• Controller-specific command scheduling
• Potential sector remapping benefits

Looking at the Ceph benchmarks mentioned:

Practical use cases where this configuration makes sense:

# Example: Creating a single-disk RAID 0 array on Linux
mdadm --create /dev/md0 --level=0 --raid-devices=1 /dev/sda
mkfs.xfs /dev/md0

This approach can be beneficial when:

• Preparing for future expansion to multi-disk RAID 0
• Maintaining consistent configuration across heterogeneous systems
• Leveraging controller-specific optimizations

Modern filesystems like ZFS and Btrfs may interact differently with single-drive RAID 0:

// ZFS example with single-disk "RAID 0"
zpool create tank /dev/disk/by-id/scsi-SINGLE_DRIVE
zfs set recordsize=128k tank

When we examine RAID 0 implementations, the conventional wisdom suggests striping data across multiple drives for performance gains. However, the concept of single-drive RAID 0 configurations challenges this paradigm. Through benchmarking tools like fio and real-world Ceph cluster tests, we observe measurable differences between these setups.

The controller treats a single physical drive as multiple logical drives for striping purposes. Here's what happens at the hardware level:

# Linux software RAID creation example
mdadm --create /dev/md0 --level=0 --raid-devices=1 /dev/sda

Benchmarks from the referenced Ceph tests show:

• 4-7% higher sequential read throughput
• Reduced command queueing overhead
• Better handling of small random writes

When configuring storage for development environments:

# Typical disk performance test command
fio --name=test --ioengine=libaio --rw=randrw --bs=4k \
    --direct=1 --size=1G --numjobs=4 --runtime=60 \
    --group_reporting

Consider single-drive RAID 0 for:

• Development VMs needing raw disk performance
• Temporary build servers
• CI/CD pipeline workers

For similar performance without RAID:

# Direct filesystem optimizations
mkfs.xfs -f -d su=64k,sw=4 /dev/sda1
mount -o noatime,nodiratime,allocsize=64k /dev/sda1 /mnt