Windows 10, kvm and iSCSI
Tempted to run Windows 10? Low on disk space? Have a NAS that supports iSCSI? Thinking what I’m thinking?
I found a really good tutorial on setting up iSCSI on a QNAP NAS, which got me most of the way there. But then I had to install Windows…
I spent some time fiddling with settings until it (mostly) worked, and thought to publish them here, in case they help anybody else who gets stuck. Here are the changes I had to make in virt-manager after following the above tutorial:
Overview: Architecture: x86_64 Chipset: Q35 (i440fx also works, see comments, thanks Kelvin!) Emulator: qemu-system-x86_64 Processor: 2 CPUs Memory: 2048MB Boot options: Enable Boot menu [X] VirtIO Disk 1 CD-ROMs: You'll need two CD-ROM drives: - SCSI CDROM for the Windows install iso - IDE CDROM for VirtIO drivers You can change the disk bus under the "Advanced options". Disk 1: - Change Disk bus to VirtIO - iSCSI should already be setup (see tutorial) Controller SCSI: Type: SCSI Model: VirtIO SCSI The remaining defaults are fine. These worked for me, some of these may be sub-optimal though.
I used a SCSI CD-ROM drive for the Windows 10 install iso, because for some stranage reason KVM didn’t seem to like launching with multiple IDE devices. I would’ve liked to use the UEFI firmware rather than SeaBIOS, but by the time I thought about this it was too late to change that setting, so I’ll leave that for another time.
During the installation, you’ll get some popups telling you that Windows can’t find the right drivers to access necessary hardware. First, you’ll need to use the “RedHat VirtIO SCSI pass-through controller” driver (to access the SCSI CD-ROM apparently), then later on the “RedHat VirtIO SCSI controller” one to access the disk.
One strange issue that I noticed was that after a reboot, booting from the HDD would fail; the VM would just go into a reboot loop. To work around this, I just used the “Force Off” power button option, and then started the VM again using the Play button – then the VM would boot again just fine.
Oh, did I mention this is very slow? It’s probably at least partially my NAS’ fault, which only seems to do ~30MB/s read/write speeds over the network (RAID 1 – it’s mostly there for my critical data after all). But hey, it works. I’ll use it to debug some Windows client / Linux server stuff; it should be quicker than updating servers and rebooting to switch OSes.