NFS datastore in Read-Only state due to 100% capacity - ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

• Virtual Machines (VMs) residing on an NFS datastore become unresponsive and inaccessible. Attempts to free space by deleting files via vCenter Server, ESXi Host Client, or the ESXi Command Line (SSH) fail consistently.
  
  
• VMs are in an unresponsive or "Inaccessible" state.
• NFS datastore reports 99.99% or 100% utilization.
• File deletion attempts return errors indicating the filesystem is read-only.
  
• The storage team confirms the backend physical pool is exhausted.

Environment

VMware vSphere ESXi 8.x

Cause

• The underlying storage pool has reached its maximum physical capacity.
  
  
• As a protective measure, the storage array has automatically placed the storage pool and its associated NFS exports into a Read-Only state.
  
  
• Because this lock is enforced at the array level, the ESXi hypervisor cannot perform any write or delete operations.

Resolution

Because the NFS datastore has reached full capacity, it is locked in a read-only state. Write access must be restored at the storage array before ESXi can execute any cleanup operations.

1. Contact the storage vendor immediately to address the physical pool exhaustion and remove the read-only restriction.

2. Expand the physical storage pool to provide immediate headroom

3. Work with the vendor to perform a corrective action, to restore write access:

4. Once the hardware-level read-only lock is removed, use the ESXi CLI or vSphere Client to delete unused virtual disks (.vmdk), snapshots, or unregistered VMs.