On Tue, Sep 23, 2014 at 06:54:48PM +0000, Boylan, Ross wrote: > I have a couple of SATA disks (software RAID on some partitions) with a > system that has become unreliable on them. I plan to add more disks and > install a new system on them (Debian wheezy). I will still need to run > things on the old OS (simultaneously running the new OS) to migrate. > > Is there a way I can use the 2 old physical disks in a VM? How? > > Searching suggests that I can't simply say -hda /dev/sdc. There are some > references to using virtio, but it isn't clear to me if this would enable me > to use the physical disk as is.
In some cases you can simply point QEMU at /dev/sdc and it will boot without a hitch. However, it depends on the guest operating system. Windows is fussy about hardware changes and may refuse to boot. Modern Linux distros tend to be okay. Booting from a pre-existing physical disk works best when the hardware changes that the guest sees are minimal. Even in a Linux guest there could be a problem if /etc/fstab uses device names like /dev/sda instead of disk labels because the device name could change if the hardware changes (e.g. virtio disks are named /dev/vda). If you are familiar with moving disks between physical machines or rescuing broken systems that don't boot, then booting a pre-existing physical disk inside KVM should feel familiar. You may also want to look at p2v migration tools: http://libguestfs.org/virt-v2v/ Good luck! Stefan
pgp5aF0DbrZSj.pgp
Description: PGP signature
