I'm building an virtual environment for a small business. It is based around a single ESXi 5.1 host, which will host half a dozen or so VMs. I'm having some doubts regarding how to implement the storage though. I naturally want the datastore to be fault tolerant, but I can't get the funds for a separate storage machine, nor expensive hardware RAID solutions, so I would like to use some software RAID (lvm/mdadm, most likely). How can this be implemented? My only idea so far would be to create a VM which has the storage adapter as passthrough, puts some software RAID on top of the disks and then presents the resulting volumes "back" to the ESXi host which then creates a datastore from which other VMs get their storage presented.

This does seem kind of round-about, do I have any better options? From my research, passthrough seems to come with quite a few drawbacks, such as no suspend/resume etc.