I'm looking for virtualisation solutions for storage and OS for a home server. A sort of private cloud where I manage the storage space independently of the VM one.

This question focus on storage management. (I have another question related to the VM/compute instance management).

Here my environement and wishes.

• Server: HP Proliant MicroServer with 8 GB RAM (AMD Turion dual core with AMD-V technology) with 1 250GB system disk and up to 4 HDD (2 TB) for "data"
• OS types: only Linux (perhaps a *BSD VM in the future)
• Linux distributions do not matter, I'm familiar with RHEL, Fedora, Suse, Ubuntu, but any other recommandation will be fine
• The 4 HDD is going to be a software RAID array, probably RAID 5.
• storage should be "virtualised/cloudified":
  • easy to extend: if I add a NAS on the network, I can include the NAS space capacity within this storage space as one virtual disk. This can be a NAS, an external HDD or another server.
  • cluster FS or S3 style space or OpenStack block storage? Whatever is easier to manage/maintain and easy to integrate/plug to VM/compute instance.

I would prefer free (libre, as in a free speach) and open source tools. But it does not have to be free as in a free beer.

Note: the VMs I intend to run on top of this server are one dedicated to backup, one for a "owncloud/dropbox"-like service and perhaps one for media server (hosting video and photos). I'm not sure if traditional VMs or compute instance are the most suitable for this.