virtualbox.org

I'd like to simulate a firmware or SATA RAID (as found on NVRAID motherboards) so that I can test and troubleshoot OS support for that type of RAID in a guest-vm before natively installing an OS on it. Is this currently possible?

Support for firmware RAID in Linux is spotty (see https://help.ubuntu.com/community/FakeRaidHowto for an example). Support for nested RAID levels (like 1+0) is worse. Rather than gamble on installing a Linux OS on host hardware with nested firmware RAID, I'd like to do it in a virtualized guest with multiple VDI or VMDK files first to make sure it'll work, and maybe fix what is holding support back.

It seems like Linux support is not progressing quickly here because testing it is a pretty risky endeavor. On the one hand, firmware RAID motherboards are cheap and pretty common. Dell machines even have this capability. Disks to populate nested RAID levels are cheap, too. On the other hand, data is not cheap, so losing it stinks. I can't replace the digital pictures or home movies of my family, and keeping them on DVD even temporarily has proved cumbersome and error prone (CRC errors only seem to pop-up when you least want them to).

If this is not a capability in VirtualBox, where would be a good place in OSE to implement it?

After this mulled in the back of mind for a while, this probably would need to be presented to guests as a new hard disk controller. On top of that, there would need to be some way to initialize RAID arrays of virtual hard disks prior to guest boot up. Normally this would be done for physical hard disks in a physical machine's BIOS (more specifically the BIOS of the RAID controller). But, maybe that could be a vboxmanage function or part of the GUI.

Fake RAID is not very well supported in Linux because it is not much used - people mostly either use proper hardware raid cards, or software (mdadm) raid. I know there are reasons for using fake raid, as mentioned in the link you gave. But software mdadm raid is more flexible and generally faster, and thus a better choice if possible.

I have a virtual machine with two VDI disks, one on each of my host's physical disks. Installation using Ubuntu's alternate install CD was straightforward, and the result is that disk access on that virtual machine is faster than on the XP host.