Hyper-V with no SAN

Hi, need some input please.  Where I work, there is a Microsoft 2008 R2 Enterprise server that’s got Hyper-V running with 4 VM’s – there is no SAN or storage solution – all running on this server.  I have been asked to set up another Hyper-V server as a ‘backup solution’ to the VM’s on the first host Hyper-V– with no SAN or storage solution – and I’m against the idea – because there is no SAN or storage solution.

What would be the risks in setting up this type of scenario?  I need something to take to the table when I'm asked again, please.

Thanks