How to Fix Virtual Machine Disk Consolidation Is Needed?

VMware vSphere is the popular virtualization solution, which helps companies and organizations easily deploy virtual environment. Although the server virtualization technology is already in its mature state, there is still a lot of maintenance work to do every day and sometimes issues would trouble the IT administrators.

"Servers were always fine till I got the error message 'virtual machine disk consolidation is needed'. I've checked the issue on Internet and it looks like the issue of snapshot. Does virtual machine consolidation needed status degrade VM performance? How could I fix the issue step by step?"

This error message often appears in VM summary tab in vSphere client after snapshot deleting. Virtual machine disk consolidation means consolidating the snapshot of certain VM and cleaning up any discrepancies of snapshot.

You would know why you need to do that and how to fix the issue in the following content.

Why is it needed to consolidate the virtual machine disk?

In the situation, you might not find the information of VM snapshot but could see the delta files in the properties of VM or see virtual machine disks consolidation is needed error but have no snapshots. The possible causes are as follows:

1. After you make VM backup, the snapshots are not properly deleted.

2. Virtual machine disk consolidation could not be completed because of not enough space on the datastore. 

3. If you are using a third-party VM backup solution, snapshot files might be locked by it. The third-party software might also cause failed snapshot deleting or backup creation.

4. There might be issues with vCenter server and ESXi host connectivity.

5. There are too many VM snapshots and consolidation fails. 32 is the recommended maximum number.

6. The consolidation might be in process because of larger files, but the alert still shows up. If you have performed disk consolidation but find that VMware disk consolidation not working, it might be because the task hasn't been completed.

How do you fix VMware ESXi disk consolidation issue?

In the last section, you have known the possible causes of the issue so you could troubleshoot it according to the real situation. Also, you could use the following solutions to fix the issue.

If you are worried that performing virtual machine disk consolidation might lead to data loss, backup VM before the operation.

Solution 1. Consolidate the virtual disk

Since the system has clearly demanded the operation of consolidation, you just need to perform it.

Just log into vSphere client > locate the problematic VM > right-click the VM > select Snapshots > select Consolidate > you would be informed with the message This operation consolidates all redundant redo logs on your virtual machine. Are you sure you want to continue? and select Yes. It would take some time if the snapshots are large.

Solution 2. Delete snapshots in Snapshot Manager

This is the solution from a member of VMware community. If you cannot find the "invisible" snapshot in Snapshot Manager or cannot delete or consolidate snapshots (Consolidate option is greyed-out), then create a new snapshot to have a further operation.

Log into vSphere client > locate the problematic VM > right-click the VM > select Snapshot > select Take Snapshot > name the snapshot > click OK > right click the VM again > select Snapshot > select Manage Snapshots > select DELETE ALL

Solution 3. Consolidate snapshot with PowerCLI

This is also a solution from VMware community and some members think it's useful.

1. Download the .vmx and open it with a text editor find the line that has the virtual disk files configured scsi0:0.fileName = "virtual-machine-000001.vmdk" and remove "-000001" so you are left with scsi0:0.fileName = "virtual-machine.vmdk" save the file.

2. Rename the .vmx file on the datastore to .old and upload the edited .vmx file.

3. Either reload the VM by using PowerCLI or remove the VM from the Inventory and re-add it again.

4. Power on the VM.

5. If you get the "Virtual Disk Consolidation needed" message, go to the Snapshot menu and click "Consolidate" it should run correctly now and remove the message.

6. Manually remove the unused files from the datastore .old, -000001.vmdk and -000001-flat.vmdk.

Sum Up

"Virtual machine disk consolidation is needed" alert often appears after incorrect snapshot deleting or other situations. The possible reasons have been listed in this passage so you could troubleshoot the issue by yourself. Also, you could use the 3 solutions in this passage to solve the problem.

To always avoid data loss, it is suggested to backup your virtual machines. Vinchin Backup & Recovery supports automated and agentless backup for VMware virtual machines. You could try 60-day full-featured free trial first to experience a brand-new effortless backup solution.