IssueTracker

Problem you have encountered:

We are seeking comprehensive guidance on best practices for reducing the disk size of our Google Compute Engine virtual machines (VMs) while minimizing service interruption. We have VMs with over-provisioned disks and want to reclaim unused space. We are concerned about potential data loss, service disruptions, and performance impacts during the resizing process. We need a clear and safe workflow.

Specifically, we are looking for information on:

Recommended Disk Resizing Methodology: What are the most efficient approaches to reduce disk size without extended downtime? Are there specific tools or techniques in GCP that facilitate minimal-disruption disk resizing?
Potential Risk Mitigation: What pre-resizing checks or validations do you recommend? How can we ensure data integrity during the disk reduction process?
Performance Considerations: Are there performance implications when reducing disk size? What impact might disk resizing have on I/O operations and VM performance?
Step-by-Step Recommended Workflow: Could you provide a detailed workflow for safely reducing VM disk size? What are the critical steps to prevent data loss or service interruption?
Backup and Rollback Strategies: What backup procedures should be implemented before attempting disk size reduction? What rollback mechanisms are available if the resizing encounters issues?
What you expected to happen:

We expect to receive clear and concise guidance from GCP support on the best practices for reducing VM disk sizes, including:

A recommended, low-downtime resizing methodology.
Specific tools and techniques within GCP to facilitate resizing.
Risk mitigation strategies to ensure data integrity.
Information on potential performance impacts.
A detailed, step-by-step workflow for safe resizing.
Recommended backup and rollback procedures.
Steps to reproduce:

This is a request for best practices and guidance rather than a specific bug. Therefore, there are no concrete steps to reproduce a problem. However, the scenario can be summarized as follows:

We have existing GCP Compute Engine VMs with attached persistent disks.
These disks are over-provisioned, containing unused space.
We want to reduce the size of these disks without significant downtime or data loss.
Other information (workarounds you have tried, documentation consulted, etc):

We have explored the following GCP documentation but require further clarification and best-practice recommendations:

Resizing persistent disks [invalid URL removed] - While this document explains how to resize disks, it doesn't provide detailed guidance on minimizing downtime or mitigating risks specifically for shrinking disks. It primarily focuses on increasing disk size.
We have considered creating snapshots and new disks with smaller sizes, but this involves downtime for data transfer and instance recreation, which we want to minimize.
We have not yet attempted any disk shrinking operations due to concerns about data loss and service disruption. We are seeking expert guidance before proceeding. We are particularly interested in in-place resizing options if they exist and are safe.

We are looking for a best practice document, or a detailed explanation from GCP support, on how to safely and efficiently reduce disk sizes on our VMs.