The following error appears when performing a backup or virtual export of a VM in VMware:
“Creating virtual machine snapshot on <AgentName>- 25.8.2013 21:05:39 failed with Replay.Common.Implementation.Virtualization.VSphereApi.EsxRemoteException: Task ‘CreateSnapshot_Task failed: File <AgentName>/<AgentName>.vmx is larger than the maximum size supported by datastore ‘[VMFS]”
Limitations exist with VMware environments that dictate the size of virtual standby exports. For example, if the datastore to which the VMware export is being performed is configured with a block size of 4MB, the maximum file size is 1024GB. Also, a 1024GB volume has a maximum VMware snapshot file size of 8GB. The maximum exportable size is equal to the VMDK size and snapshot file combined. In cases where the snapshot file becomes large, the maximum size of an exported agent volume set may be smaller. VMware recommends allowing for the following “worst case scenarios.” The snapshot file size is referred to as “overhead.”
NOTE: Though VMware’s VMFS5 and VMFS3 support files larger than 2TB, the current maximum VMDK file size is 2048GB minus 512 Bytes.
| Block Size | Maximum File Size |
| 1 MB | 256 GB – 512 Bytes |
| 2 MB | 512 GB – 512 Bytes |
| 4 MB | 1 TB – 512 Bytes |
| 8 MB | 2 TB – 512 Bytes |
| Maximum VMDK Size | Maximum Overhead | Maximum Size Less Overhead |
| 256 GB – 512 Bytes | ~ 2 GB | 254 GB |
| 512 GB – 512 Bytes | ~ 4 GB | 508 GB |
| 1 TB – 512 Bytes | ~ 8 GB | 1016 GB |
| 2 TB – 512 Bytes | ~ 16 GB | 2032 GB |
For more information, please refer to the following articles:
