"Operation Failed: A general system error occurred" error when creating a snapshot on a powered ON VM

Products

• VMware vSphere ESXi

Issue/Introduction

• Creating a snapshot on a powered ON VM failed with below error:

Operation Failed!
Task name Create virtual machine snapshot
Target VMNAME
Status A general system error occurred

• After the snapshot task failure, the disk size is '0' MB:

In /var/run/log/hostd.log:

2025-01-15T13:53:04.112Z info hostd[2880702] [Originator@6876 sub=Vmsvc.vm:/vmfs/volumes/xxxxxxxxx-xxxxxxxx/VMNAME/VMNAME.vmx opID=m3rdm0mg-5368166-auto-3723r-h5:70312635-24-01-01-01-02-dd-a2f7] Snapshot tree refresh ignored because storage is not accessible.
2025-01-15T13:53:04.123Z warning hostd[2880702] [Originator@6876 sub=Vmsvc.vm:/vmfs/volumes/xxxxxxxxx-xxxxxxxx/VMNAME/VMNAME.vmx opID=m3rdm0mg-5368166-auto-3723r-h5:70312635-24-01-01-01-02-dd-a2f7] PopulateCache failed: _diskAccess : true, _storageAccessible : false
2025-01-15T13:53:04.124Z warning hostd[2880702] [Originator@6876 sub=Vigor.Vmsvc.vm:/vmfs/volumes/xxxxxxxxx-xxxxxxxx/VMNAME/VMNAME.vmx opID=m3rdm0mg-5368166-auto-3723r-h5:70312635-24-01-01-01-02-dd-a2f7] Disk properties cache miss for disk path: /vmfs/volumes/xxxxxxxxx-xxxxxxxx/VMNAME/VMNAME-000001.vmdk.

The datastore name is also logged in hostd.log:

2025-01-15T13:53:04.152Z warning hostd[2880702] [Originator@6876 sub=Vmsvc.vm:/vmfs/volumes/xxxxxxxxx-xxxxxxxx/VMNAME/VMNAME.vmx opID=m3rdm0mg-5368166-auto-3723r-h5:70312635-24-01-01-01-02-dd-a2f7] UpdateStorageAccessibilityStatusInt: The datastore <datastore_name> is not accessible
2025-01-15T13:53:04.152Z info hostd[2880702] [Originator@6876 sub=Vimsvc.ha-eventmgr opID=m3rdm0mg-5368166-auto-3723r-h5:70312635-24-01-01-01-02-dd-a2f7] Event 8383590 : Some of the disks of the virtual machine VMNAME on host ESXI_HOST_NAME failed to load. The information present for them in the virtual machine configuration may be incomplete

Environment

VMware vSphere ESXi 7.x
VMware vSphere ESXi 8.x

Cause

• An ISO is mounted on the VM from an inaccessible datastore.
• This can happen when an ISO has been attached to the VM and that ISO gets moved to a different datastore; or was deleted without removing it from the virtual machine beforehand.

Resolution

• Using the vSphere Client, edit the virtual machine's configuration and detach any inaccessible ISO files.

Additional Information

Also refer: VMDK disk show zero size after snapshot operation