Fixed: VMware Disk Consolidation Stuck at 0

VMware vSphere, a widely used virtualization platform, often encounters issues when managing virtual machine (VM) snapshots, one of which is that the consolidation process gets stuck at 0% when the “Need to consolidate VM disks” warning appears. When the VMware disk consolidation stuck at 0% issue occurs, it can lead to performance degradation, overuse of storage space, and potential virtual machine instability. In this article, we will cover the causes of the problem and how to resolve it.

What Causes VMware Disk Consolidation to Get Stuck

1. Locked or Corrupted VMDK Files

If another process or host locks a virtual disk (.vmdk) file, consolidation may fail.

Corruption in snapshot files or disks can also prevent consolidation.

2. Insufficient Storage Space

The consolidation process requires enough free space on the datastore to merge snapshot data.

The process may hang at 0% if the datastore is nearly full.

3. Active Virtual Machine Processes

If the VM is running high disk I/O operations, consolidation might be delayed or fail.

Large snapshots can take time to merge, making it seem like consolidation is stuck.

How to Fix VMware Disk Consolidation Stuck at 0

1. Verify and Free Up Storage Space

Navigate to vSphere Client > Datastores and check the available space in the datastore.

If there is not enough space, delete unnecessary snapshots or migrate the virtual machine to another datastore.

2. Manually Consolidate Disks

In the vSphere Client, right-click the affected virtual machine, and select Snapshot > Consolidate.

If the process is still stuck, try creating a new snapshot manually and then merge it again.

3. Restart the Management Agent on the ESXi host

If the merge hangs, restarting the VMware Management Service can help:

Connect to ESXi host via SSH.

Run the following command:

Retry the consolidation process.

4. Check for Locked VMDK Files

Identify locked files by running:

If locked, check which ESXi host has the lock and restart the host if needed.

5. Remove and Re-add the VM to Inventory

• Power off the VM.
• Remove it from the inventory (but do not delete the VM files).
• Re-add the VM by browsing the datastore and selecting the VMX file.
• Retry consolidation.

6. Restart vCenter Server Services

If vSphere Client becomes unresponsive, restart vCenter services:

7. Clone the VM as a Last Resort

If all else fails:

• Clone the VM without snapshots.
• Power off and delete the original VM.

Free Backup Software to Protect VMs from Errors

In addition to the disk consolidation stuck problem, you may also encounter other unexpected problems when operating VMware. To ensure data safety when problems occur, you can use reliable backup software AOMEI Cyber ​​Backup. It is specially designed for VMware VMs and can automate the virtual machine backup process, monitor the backup status, and send email notifications when errors occur.

Automated Backup: You can configure a backup schedule where the backup task will be executed automatically at a specified time.
Instant Disaster Recovery: In the event of a VMware crash, quickly restore VMware to a normal state, reducing business-critical downtime.
Backup to all locations: It supports backup VMware virtual machines to external hard drives, local storage, NAS drives, network share, etc.
Simplified Backup: Simply set up a policy and execute it automatically, which greatly improves work efficiency and reduces human error.

3 Easy Steps to Create Automatic Backup Tasks of VMware ESXi VMs

Step 1. In AOMEI Cyber Backup, navigate to Source Device > VMware > + Add VMware Device to add vCenter or Standalone ESXi host as the source device. And click Confirm.

Step 2. Navigate to Backup Task > + Create New Task, and then set Task Name, Backup Type, Device, Target, and Schedule.

• Device: you can backup multiple VMs on the host.
• Target: you can select to back up to a local path, or a network path. Used paths will be saved in Favorite Storage for handy selection.
• Schedule: you can choose to perform full, differential, or incremental backup, and automate execution daily, weekly, or monthly according to the frequency you specified.

Step 3. Click Start Backup, and you can select Add the schedule and start backup now, or Add the schedule only.

Conclusion

Disk consolidation stuck at 0% in VMware is a common issue, but you can resolve it with the steps provided in this article. By checking the storage space, restarting the service, dealing with locked files, and trying manual consolidation, one can successfully resolve the issue and keep the virtual environment stable.