Datastore is full, need to free disk space

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

This article provides steps to recover from a situation where a VMware vSphere datastore has reached capacity, causing virtual machines (VMs) to become unresponsive, fail to power on, or failed consolidations.

Environment

VMware ESXi 8

VMware ESXi 9

 

Cause

A datastore reaches critical capacity, preventing the creation of mandatory Virtual Machine Swap files (.vswp) or metadata updates required for online Storage vMotion. This is often caused by snapshot growth (e.g., failed backup consolidation), large log files, or orphaned files.

Resolution

1. Snapshot Identification and Consolidation
   Active VM snapshots write new data to delta disks, which rapidly consumes datastore space.
   • Verify active snapshots using the vSphere Client.
   • Perform snapshot consolidation (sufficient free space is required).
2. Manual Methods for Reclaiming Space
   If space constraints prevent snapshot consolidation, apply the following steps to free up capacity:
   • Shut Down Unresponsive VMs: Shutting down a VM removes its swap file (.vswp), releasing capacity equivalent to its unreserved memory.
   • Delete ISO Files: Locate and purge unnecessary installation ISOs stored on the datastore.
   • Clear Historical Log Files: Establish an SSH connection to the ESXi host and remove obsolete or oversized vmware-##.log files.
   • Execute Cold Migration: Power off the VM and migrate it offline to an alternate datastore, bypassing source datastore metadata overhead.
3. Storage vMotion Relocation
   After recovering sufficient operating space, initiate Storage vMotion to transfer virtual disks to datastores with adequate available storage capacity.

Additional Information

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Japanese KB: データストアの容量が不足しています。ディスク領域を解放する必要があります。