You can take virtual machine snapshots by using vmware-cmd.

You can take a snapshot while a virtual machine is running, shut down, or suspended. If you are in the process of suspending a virtual machine, wait until the suspend operation has finished before taking a snapshot.

If a virtual machine has multiple disks in different disk modes, you must shut down the virtual machine before taking a snapshot. For example, if you have a special-purpose configuration that requires you to use an independent disk, you must shut down the virtual machine before taking a snapshot.

Procedure
1

(Optional) If the virtual machine has multiple disks in different disk modes, shut down the virtual machine. 

vmware-cmd -H <vc_system> -U <user> -P <password> --vihost <esx_host> /vmfs/volumes/Storage2/testvm/testvm.vmx stop soft
2

(Optional) Check that the shut down operation has been completed. 

vmware-cmd -H <vc_system> -U <user> -P <password> --vihost <esx_host> /vmfs/volumes/Storage2/testvm/testvm.vmx getstate
3

Run vmware-cmd with the createsnapshot option.

You must specify the description, quiesce flag (0 or 1) and memory flag (0 or 1). 

vmware-cmd -H <vc_system> -U <user> -P <password> --vihost <esx_host> /vmfs/volumes/Storage2/testvm/testvm.vmx createsnapshot VM1Aug09 'test snapshot August 09' 0 0
4

Check that the virtual machine has a snapshot by using the hassnapshot option.

The call returns 1 if the virtual machine has a snapshot and returns 0 otherwise. 

vmware-cmd -H <vc_system> -U <user> -P <password> --vihost <esx_host> /vmfs/volumes/Storage2/testvm/testvm.vmx hassnapshot
 
hassnapshot () = 1