How to choose between pd-balanced pd-ssd pd-extreme and Hyperdisk

By Sai Kiran Pandrala · Last verified: 2026-05-31 · Source: community Q&A, Google Cloud docs, Google Cloud Community

When How to choose between pd-balanced pd-ssd pd-extreme and Hyperdisk bites you on Google Persistent Disk, the first instinct is to open a ticket. Most of the time you do not have to. The steps below are the ones Google Cloud Support would walk you through on the call.

What how to choose between pd-balanced pd-ssd pd-extreme and hyperdisk actually involves on Google Persistent Disk

This task on Persistent Disk is one of the more searched operational topics on AWS in the last 12 months. The procedure below is the path that works in a current AWS account with default IAM and standard VPC config.

The rest of this page is the structured fix path. Start with diagnose, then remediation, then the automation options so you do not have to do this by hand the next time it surfaces. Verify and safety sections at the end are the discipline that keeps the fix from regressing in production.

Diagnose first, fix second

Check the Google Cloud Service Health at status.cloud.google.com and the per-product status board for ongoing service events in your region. About one in ten user-reported outages turn out to be region-scoped Google Cloud service degradation already being tracked. Cloud Service Health also exposes an API and Eventarc events, so you can wire a Lambda hook that pages on-call only when the failure correlates with an active Cloud Service Health event in the same region and service.

Look at the Cloud Audit Log event for the failed call, even if you are not enrolled in Cloud Logging Log Router. The basic 90-day event history works for most diagnostic purposes and lives in the console under Cloud Audit Logs > Event history. Filter by event name (the API action) and time range; the event JSON shows the exact user identity, source IP, request parameters, and error code.

Pull the Google Cloud request ID from the response headers: x-goog-request-id from response headers (or the insertId field in Cloud Logging for asynchronous calls). Google Cloud Support needs these IDs to look up your call in their internal logs - without them, the first reply on a ticket will ask you to reproduce the call and capture them. Save them with a timestamp; Google Cloud Support cannot retrieve calls older than 90 days for most services.

Solution-focused remediation path

If networking is suspect, use Network Intelligence Connectivity Tests. It is the only tool that simulates the full ENI-to-ENI path including firewall rules, hierarchical firewall policies, routes, and VPC Service Controls perimeters in one call. Manual trace is slower and misses transitive issues. The analyzer charges $0.10 per analysis - cheaper than a 30-minute call with your network team.

When the fix involves a destructive operation (delete VPC endpoint, swap Cloud KMS key, rotate root credential), do it during a maintenance window with at least one teammate watching. Several Google Persistent Disk operations have implicit dependencies that only show up when traffic starts flowing again. Document the rollback path before you start, not during the incident.

When the failure happens in production but not in dev, do not just compare the IAM policy. Compare the Org Policy / RCP at the OU level, the permission boundary on the role, and the resource-based policy on the target. One of those is almost always different between accounts. Policy Intelligence recommendations bundles make this comparison routine.

Automate this fix so you do not do it twice

Add a Workflows or Cloud Tasks Automation runbook

For multi-step fixes that include a manual approval, use Workflows runbook. Document the fix as a runbook with workflows.executions.approve steps where a human signs off and workflows.steps.callApi steps where the runbook calls the Google Cloud API. Approvers are notified by SNS; the runbook execution shows up in Cloud Audit Logs with the approver's identity attached. This makes audit trails easy and stops production fixes from being one-person operations.

Codify the fix in Terraform or Deployment Manager

When you reach for the console to fix the same issue twice, the third occurrence should be solved in IaC, not in the console. Terraform's terraform import and Deployment Manager or Terraform's resource importer let you adopt the existing resource into state without recreating it. Lock the corrected attribute behind a variable so the next operator does not have to rediscover the value. Add a moved {} block or Deployment Manager or Terraform resource refactor to keep the diff clean.

Add a Cloud Monitoring alert policy so you know next time

The cheapest way to never see the same incident twice is a Cloud Monitoring alert policy on the metric that would have warned you. For Google Persistent Disk, the relevant metrics live under compute.googleapis.com/google namespace or under custom metrics published by your Cloud Run service or GKE pod. Set thresholds based on observed normal range plus one or two standard deviations, not on round-number guesses. Cloud Monitoring anomaly-based alert policies remove the threshold-guessing problem entirely for metrics with regular seasonality.

Common pitfalls and what to watch for

The pitfall most teams hit on Google Persistent Disk is moving too fast and skipping the read-only validation step. Before any write, list the current state and save it. Google Cloud APIs are eventually consistent for many resource types, so the validation snapshot is your only reliable reference if you need to undo. Save the output of the describe call to S3, not to your laptop.

Second pitfall: confusing IAM permission errors with networking errors. AccessDenied can be IAM (policy missing), networking (VPC endpoint policy blocking the call), or KMS (key policy missing). The error string looks identical for all three. Distinguish by looking at the Cloud Audit Log event's errorCode and the encoded authorization message; do not assume IAM is the culprit just because the message says AccessDenied.

Verify the fix worked

• Reproduce the original symptom path. If it still surfaces in any account or region or IAM role or service account, you have not fixed it.
• Watch for 24 to 48 hours. Cloud Monitoring metrics and Cloud Asset Inventory can mask issues with cached health for 6 to 12 hours, especially Cloud CDN and Cloud DNS.
• Run a smoke test under realistic load. Happy-path tests miss race conditions and IAM session-cache issues.
• Capture the new state in a runbook so the next person on call does not have to rediscover this. Push it to Confluence or your team wiki, not into Slack.
• If the fix involved a permission change, run IAM Access Analyzer one more time to confirm you did not open a separate hole while closing this one.

Safety, rollback, blast radius

• Test in a non-production account if your environment has Resource Manager and Organization Policy or Cloud Resource Manager (organizations, folders, projects). The cost of one sandbox account is cheaper than one rollback meeting.
• Export the existing config before changing it. Most Google Persistent Disk resources support describe + export to JSON via CLI - capture that to source control before you start.
• Know your rollback path. Some Google Persistent Disk operations are one-way (region migration, account-level feature opt-in, Cloud KMS key deletion past pending window). Confirm reversibility on the Google Cloud doc before you commit.
• Be aware of cross-service impact. IAM role or service account changes ripple to every service trusting that role. Cloud KMS key changes break every workload depending on that key. VPC endpoint changes affect every VPC consumer of that endpoint.
• Maintenance window discipline: if the change touches DNS, certificate rotation, or anything that emits TLS handshakes, line up a window with stakeholder notification, not a heroic mid-day swap.

FAQ

Related fixes

Related guides worth a look while you sort this one out:

• How to convert pd-ssd to Hyperdisk Balanced
• How to calculate Hyperdisk Balanced IOPS throughput
• How to migrate from pd-standard to pd-balanced without downtime
• How to migrate snapshots from PD to Hyperdisk
• How to provision Hyperdisk Throughput ML Extreme
• How to choose between SSD and HDD storage