As far as I'm aware, ASM is the only recommended solution for dynamic device and disk space management. Oracle VM Server for x86 is the recommended solution for Oracle product virtualization. I think Oracle added support for VMware ESX or vSphere suite to their support portfolio recently. If you do not want to use ASM then you will have to deal with the OS, in which case LVM is probably the best way to manage your disk space. If you are using virtualization and need to increase any volume size, you would probably rather want to add additional virtual disks to an existing LVM volume instead of resizing the phycial device.