How to Choose the Right Cloud Storage: 4 Simple Mnemonics for Easy Selection

Introduction

With the growing variety of cloud storage products, deciding between cloud disk, file service, and object storage can be challenging. This guide offers four concise mnemonics that let you select the right storage for your application without deep theoretical knowledge.

Four Mnemonics

“First use cloud disk, generic specs are most versatile.” Cloud disks provide a distributed‑storage experience similar to local block devices, offering high reliability and elastic expansion. They are ideal for initial cloud migration and latency‑sensitive workloads such as databases.

Initial cloud migration – reduces learning cost by mimicking local storage. Latency‑sensitive single‑node workloads – typical for small, frequent I/O operations.

Choose a cloud disk size and attach it to your VM. Three disk types exist: performance‑SSD, general‑SSD, and capacity‑HDD. Use general‑SSD for balanced cost and performance, performance‑SSD for high IOPS, and HDD for large, infrequently accessed data.

“Shared data, high concurrency – file and object both fit.” When many VMs need shared access or you require automatic scaling to petabyte levels, consider cloud file service or object storage.

File service supports POSIX semantics, allowing in‑place modifications; object storage requires download‑modify‑upload cycles. File service suits frequent read‑write scenarios, while object storage excels at massive concurrent reads, CDN delivery, data lifecycle management, and lowest per‑GB cost.

“Frequent reads/writes use files; many reads use objects.” File service allows appends and mid‑file updates, making it better for workloads that constantly modify data. Object storage is optimal when read traffic dominates and you need features like CDN, image processing, or cross‑region replication.

“Fine‑tune performance: split by concurrency and latency.” Performance bottlenecks arise from throughput, IOPS, or latency. Identify the limiting factor by examining I/O size and parallelism: small I/O (<128 KB) often hits IOPS limits, large I/O (>128 KB) hits throughput, and serial requests expose latency.

Typical latency hierarchy (fastest to slowest): local disk < cloud disk < cloud file service < object storage. Optimizations include increasing request concurrency, distributing load across multiple storage units, or placing latency‑critical I/O on faster tiers.

By applying these four mnemonics and matching your functional, performance, and migration requirements, you can quickly choose the most appropriate cloud storage solution.