Cloud Storage

Google Cloud Storage (GCS) is a unified object storage service for any amount of data. It serves static assets, backups, data lakes, and application data with global availability and strong consistency. GCS is the default object store for GCP — nearly every service integrates with it natively.

Storage Classes link

All classes offer 11 nines (99.999999999%) durability through redundant storage across multiple devices and locations.

Location Types link

Create a Bucket link

  gsutil mb -l us-central1 -c STANDARD gs://learning-gcp-dev-assets/

# Set uniform bucket-level access (recommended)
gsutil uniformbucketlevelaccess set on gs://learning-gcp-dev-assets/

# Enable versioning
gsutil versioning set on gs://learning-gcp-dev-assets/

# Set default encryption (Google-managed is default; CMEK optional)
gsutil encryption set -k \
  projects/learning-gcp-dev/locations/us-central1/keyRings/my-ring/cryptoKeys/my-key \
  gs://learning-gcp-dev-assets/
  

Bucket names are globally unique. Choose location based on latency, compliance, and cost requirements.

Upload and Download link

  # Upload a file
gsutil cp photo.jpg gs://learning-gcp-dev-assets/images/photo.jpg

# Parallel upload for large files
gsutil -m cp -r ./data/ gs://learning-gcp-dev-assets/data/

# List objects
gsutil ls -l gs://learning-gcp-dev-assets/images/

# Download
gsutil cp gs://learning-gcp-dev-assets/images/photo.jpg ./photo.jpg
  

Python SDK example:

  from google.cloud import storage

client = storage.Client()
bucket = client.bucket("learning-gcp-dev-assets")
blob = bucket.blob("images/photo.jpg")

blob.upload_from_filename("photo.jpg")

# Generate signed URL (time-limited access)
url = blob.generate_signed_url(version="v4", expiration=3600, method="GET")
print(url)
  

Lifecycle Management link

Automatically transition or delete objects:

  {
  "lifecycle": {
    "rule": [
      {
        "action": { "type": "SetStorageClass", "storageClass": "NEARLINE" },
        "condition": { "age": 30 }
      },
      {
        "action": { "type": "SetStorageClass", "storageClass": "COLDLINE" },
        "condition": { "age": 90 }
      },
      {
        "action": { "type": "Delete" },
        "condition": { "age": 365 }
      }
    ]
  }
}
  

Apply with: gsutil lifecycle set lifecycle.json gs://learning-gcp-dev-assets/

Security link

  # Grant read-only access to a service account
gsutil iam ch \
  serviceAccount:[email protected]:objectViewer \
  gs://learning-gcp-dev-assets/

# Block public access
gcloud storage buckets update gs://learning-gcp-dev-assets \
  --public-access-prevention=enforced
  

Cross-Bucket Replication link

Replicate objects to a DR bucket in another region:

  # Create DR bucket
gsutil mb -l europe-west1 -c STANDARD gs://learning-gcp-dev-assets-dr/

# Configure replication (via Terraform or Console)
# Requires versioning enabled on source bucket
  

GCS vs. Other Object Stores link

Common Patterns link

Real-World Scenario: Media Platform link

A video platform stores user uploads and serves transcoded content:

1. Upload bucket (uploads-raw) — Standard class, versioning on
2. Processing pipeline — GCS trigger → Cloud Function → transcode → output bucket
3. Delivery bucket (media-cdn) — Standard class behind Cloud CDN
4. Archive bucket — Lifecycle moves originals to Coldline after 90 days
5. IAM — upload SA has objectCreator on raw; CDN SA has objectViewer on media

Common Mistakes link

Best Practices link

• Enable uniform bucket-level access on all buckets
• Use versioning on buckets with critical data
• Apply lifecycle rules from day one
• Generate signed URLs for temporary client access instead of making objects public
• Use labels on buckets for cost allocation
• Monitor with Cloud Monitoring metrics (storage.googleapis.com/storage/total_bytes)
• Use Storage Transfer Service for large migrations from S3 or on-premises

Troubleshooting link

“Access denied” on upload:

  gsutil iam get gs://learning-gcp-dev-assets/
# Verify caller has storage.objectCreator or storage.objectAdmin
  

Slow uploads:

  gsutil -o GSUtil:parallel_composite_upload_threshold=150M \
  -m cp large-file.tar gs://learning-gcp-dev-assets/
  

Object not found after upload: Check bucket name spelling (globally unique) and object path. Use gsutil ls -r to verify.

Lifecycle rule not applying: Lifecycle actions run once per day. Verify rule JSON and check gsutil lifecycle get.

GCS is the default object store for GCP — integrate it with Compute Engine, GKE, Cloud Functions, and analytics services.

Next: Cloud SQL — managed relational databases.