KB007: Using Ursa Major Archive (Coldline Strategy)

Scope: Long-Term Data Retention Audience: Researchers needing compliance archiving or migrating “Zombie” storage. Last Updated: Feb 9, 2026

1. Overview

The Ursa Major Archive Tier utilizes Google Cloud Coldline Storage. It is designed for data that you need to keep (for grant compliance, reproducibility, or backup) but do not access frequently.

Key Rule: Accessing (reading) Coldline data incurs a Retrieval Fee. Do not use this for active analysis data. Use it for data you access less than once per quarter.

2. Cost Advantage

• Standard Storage: ~$0.020 per GB/month ($20/TB).
• Coldline Archive: ~$0.004 per GB/month ($4/TB).
• Savings: Moving 10 TB from Standard to Coldline saves ~$160/month ($1,920/year).

3. How to Archive Data

Method A: Converting an Existing Bucket (The “In-Place” Archive)

If you have a Standard bucket (gs://my-lab-data) and want to convert it to Archive:

1. Go to GCP Console: Storage Browser.
2. Select Bucket: Click the bucket name.
3. Configuration: Go to the “Configuration” tab.
4. Edit Storage Class: Change Default Storage Class to Coldline.
   • Note: This applies to new objects. To change existing objects, use a Lifecycle Rule (Method B).

Method B: Lifecycle Rule (Automatic Transition)

Best for moving data that hasn’t been touched in 30 days.

CLI Command: Create a JSON file lifecycle.json:

{
  "rule": [
    {
      "action": {
        "type": "SetStorageClass",
        "storageClass": "COLDLINE"
      },
      "condition": {
        "age": 30,
        "matchesStorageClass": ["STANDARD"]
      }
    }
  ]
}

Apply it:

gsutil lifecycle set lifecycle.json gs://my-bucket-name

Method C: Direct Upload to Archive

When uploading new backups, tag them immediately.

# Upload folder
gsutil -m cp -r -c COLDLINE ./my_local_data/ gs://my-archive-bucket/

4. Recovering from “Administrative Lock” (Zombie Storage)

If your project was Locked/Suspended due to orphaned disks:

1. Snapshot: We will create a snapshot of your disk.
2. Export: We (or you) can export that snapshot to a Coldline Bucket.
3. Delete Disk: The expensive compute disk is deleted.
4. Result: You pay for cheap Archive storage ($4/TB) instead of expensive Provisioned Disk ($100/TB).

To Request Recovery: File a ticket with Research Computing requesting “Snapshot Export to Coldline” for your locked project.