This article speaks about the error “spec.deviceChange.device” received when attempting to create snapshot on a virtual machine with “monolithicFlat” disk type.
/vmfs/volumes/<datastore_id>/<vm_name>/vmware.log
YYYY-MM-DDThh:mm:ss.718Z In(05) vcpu-0 lzh5v6zv-1649763-auto-zcys-h5:70402445-62-f1-50c5 DiskLib_IsVMFSSparseSupported: vmfssparse is not supported on /vmfs/volumes/datastore/vm_name: f532.
YYYY-MM-DDThh:mm:ss.718Z In(05) vcpu-0 lzh5v6zv-1649763-auto-zcys-h5:70402445-62-f1-50c5 DISKLIB-LIB_CREATE : DiskLibAdjustDataDiskCreateType: Overriding create type of child disk "vmfsSparse" from /vmfs/volumes/datastore/vm_name/vm_diskName-00000X.vmdk to SESPARSE because the filesystem does not support VMFSSPARSE.
YYYY-MM-DDThh:mm:ss.718Z In(05) vcpu-0 lzh5v6zv-1649763-auto-zcys-h5:70402445-62-f1-50c5 DISKLIB-LIB_CREATE : seSparse cannot be a child of monolithicFlat
YYYY-MM-DDThh:mm:ss.718Z In(05) vcpu-0 lzh5v6zv-1649763-auto-zcys-h5:70402445-62-f1-50c5 DISKLIB-LIB_CREATE : Failed to create link: One of the parameters supplied is invalid (1)
YYYY-MM-DDThh:mm:ss.718Z Er(02) vcpu-0 lzh5v6zv-1649763-auto-zcys-h5:70402445-62-f1-50c5 DISKLIB-LIB_CREATE : DiskLib_CreateChild: failed to create child disk: One of the parameters supplied is invalid (1)
/vmfs/volumes/<datastore_id>/<vm_name>
/
VMware ESXi 6.x, 7.x and 8.x
As stated on the aforementioned log snippet, snapshots on monolithicFlat disk are not permitted, they are only permitted for VMFS datatype disk.
To resolve this issue, convert the VMDK disk from a monolithic type to a VMFS type. This can be done by cloning the disk using the vmkfstools by following below steps:
vmkfstools -i /vmfs/volumes/<Datastore>/<VM_name>/<VM_diskname>.vmdk /vmfs/volumes/<Datastore>/<VM_name>/<VM_newdiskname>.vmdk
If there are multiple monolithic disks, repeat the same steps for all of them.