I'm working out how to install various OSes onto diskless servers to be run via iSCSI. The servers have no special hardware for this (no iSCSI HBAs etc.)
I briefly played with Windows Deployment Services but it seems to be about the opposite of what I want: I could be wrong but it seems designed to do a network-based install of Windows onto a system that will then boot from a local disk, whereas I want to install Windows such that it will run from an iSCSI disk, and I don't care if install media has to be inserted locally. Therefore my present approach doesn't use WDS.
This test was of Windows Server 2012 but likely applies to prior versions also.
In short, I am setting up a blank iSCSI target (I have tried several s/w vendors and it doesn't seem to make much difference although presently I'm using StarWind), and using PXE to chain to gPXE or iPXE to do an iSCSI boot (I've tried both, with similar result although I found gPXE a little easier to use.)
Of course, without an OS, the boot fails, but it leaves the LU hooked in through the BIOS disk interface such that when the local DVD-ROM is then booted, the installer sees the volume to install to.
I accomplish the boot by dropping to a gPXE prompt and typing the following commands (same in iPXE except for the interface #):
dhcp net1 set keep-san 1 sanboot iscsi:#.#.#.#::::iqn.xxxxxxxxxxxxxxxxxxx exit
Windows Server 2012 seems to install and at some point reboots. iPXE kicks in to boot from iSCSI, and the 'Metro' logo appears - so at least something did get installed to the LU. However, the screen then turns light blue and a message briefly flashes in large text, something about the "PC" (it's actually a rack server but anyway) encountering a problem but I can't read it all before it vanishes and the computer is rebooting.
Eventually I get a text screen titled
Windows Boot Manager which reads:
Windows failed to start. A recent hardware or software change might be the cause. To fix the problem: 1. Insert your Windows installation disc and restart your computer. 2. Choose your language settings, and then click "Next." 3. Click "Repair your computer." If you do not have this disc, contact your system administrator or computer manufacturer for assistance. File: \Windows\system32\ntoskrnl.exe Status: 0xc00000e9 Info: The operating system couldn't be loaded because the kernel is missing or contains errors
Those paying close attention will realize these instructions would be very difficult to follow effectively, especially on physical hardware. (By the way, I have tried installs both to physical and virtual machines, with similar results.)
I am guessing what is happening here is that Windows 2012 gets as far as it does because iPXE has hooked Interrupt 13h (BIOS disk services), but once the system has booted far enough to switch to protected mode drivers, the boot is rudely interrupted because there is no hard disk to read from and/or Windows' iSCSI initiator fails.
The iPXE I'm trying is 1.0.0+ (3fcb) and the gPXE I tried was 1.0.1.
Is it possible to have Server 2012 run off iSCSI without a hardware HBA, and if so, what might I be doing wrong?