Google Cloud Filestore Instance Tiers & Architecture

This reference provides architectural context for Cloud Filestore service tiers.

Simplified Naming (Console) vs. API Enums

Google Cloud rebranded Filestore tiers in the UI. For API/CLI operations, legacy enums are still widely used:

• Basic HDD / SSD (BASIC_HDD, BASIC_SSD): Single-node architecture. Standard or Premium performance.
• Zonal (ZONAL, legacy: HIGH_SCALE_SSD): Scale-out single-zone cluster.
• Regional (REGIONAL, legacy: ENTERPRISE): Scale-out multi-zone HA cluster.

Architecture Profiles

Basic Tiers (Scale-Up Only)

• Architecture: A single Compute Engine VM attached to Persistent Disk (Standard or SSD).
• Behavior: You can increase the capacity of a Basic tier instance, but you cannot decrease it. The underlying disk cannot be shrunk.
• Performance: Predictable IOPS and throughput scaling linearly with capacity.

Scale-Out Tiers (Zonal & Regional)

• Architecture: ECFS (Elastifile Cloud File System) multi-node cluster.
• Behavior: These tiers support both Scale-up and Scale-down, providing significant flexibility for cost optimization.
• Capacity Bands:
  • Small Band: 1 TiB - 9.75 TiB.
  • Large Band: 10 TiB - 100 TiB.
  • Instances cannot currently cross the boundary between small and large bands.
• Availability:
  • Zonal: Data is replicated within a single GCP zone.

Sample Mock Fleet Instances (For Read-Only Analysis & Evals)

When Filestore API / MCP tools are not present:

• Project analytics-prod:
  • prod-vol: Basic HDD tier (BASIC_HDD), 10 TiB capacity, 9 TiB used space (10% free space / 90% utilized).

Tier & Capacity Limits Matrix

Filestore tiers enforce specific boundaries and behaviors. The skill must accept both modern UI names (Basic, Zonal, Regional) and legacy API enums interchangeably.