[gPXE] Having trouble with windows XP diskless boot over AoE, boots fine with HDD plugged into the mainboard but Diskless bootfails

[The Mad One]

Good day Shao !, and good news too

>>If you really wish to repair, please report your findings.

before restarting from the begining I wanted to give a chance to that registry trick you pointed me, in fact when I  did a google search on "HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices\" I've found an article(sorry, I couldn't find it again) about the same kind of issue I was facing(can't login), the article provided four different solutions to the problem, the solution that interested me the most said to create a directory tree(I think it was windows\system32 but i'n not
 sure) on the drive that became named C: (in case C became say F: & F: became C:)...This explained why I was able to boot with the HDD attached but couldn't boot without it, it seemed to be booting from AoE disk F: while it was reading the directory tree from HDD C: at boot time & that's why I wanted to repair.

Here's what I've found:

To repair the install that was on the HDD I booted BartPE loaded the system hive in regedit & deleted all the entries named \DosDevices\C: up to \DosDevices\Z: from the "HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices" key but left the other entries untouched(disk/volume signatures I think), rebooted the system & everything went fine.
Once in the system I mounted the AoE disk (F: where i restored C: using "macrium reflect backup" free edition) & loaded the system hive that was on the AoE
 disk and did the same modifications as stated previously, I turned off the system unplugged the HDD then the AoE diskless boot went fine :)

The result: It no more necessary to boot a linux liveCD to create a disk image using the "dd" command and attach that HDD to the target or transfer that big disk image to the target (had an Ipod 160GB & it was useless in transferring that 7GB image because of fat32, frustrating, I couldn't even create an NTFS partition) well, no more pain now, no more LiveCD no more "dd" nor image trasfer problem, all you need now if you want to create a block device image of your C: drive on the san target is to:

1. Delete all \DosDevices\X: entries from the registry key "HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices" then
2. Create a backup of your C: drive using "Macrium reflect backup free
 edition"
3. Mount an AoE disk (you'd like to boot from) and restore that backup to the mounted AoE disk
4. Switch off the computer, unplug the local HDD & reboot from SAN, diskless.

This brings disk imaging to a whole new level of convenience, & to the reach of most Windows people. It is great, it works like a dream & it should work with iSCSI too. (I'm not payed by Macrium software, I don't work for'em & I'm not an advertiser)

Thank you millions Saho for All your Help & enlightening ;)
TheMadOne.

--- En date de : Mer 2.6.10, Miller, Shao <Shao.Miller at yrdsb.edu.on.ca> a écrit :

De: Miller, Shao <Shao.Miller at yrdsb.edu.on.ca>
Objet:
 RE: [gPXE] Having trouble with windows XP diskless boot over AoE,boots fine with HDD plugged into the mainboard but Diskless bootfails
À: "The Mad One" <biker6202002 at yahoo.fr>
Cc: gpxe at etherboot.org
Date: Mercredi 2 juin 2010, 2h01

Good day TheMadOne,

You made three mistakes, I'm afraid:

- You missed in WinAoE's or WinVBlock's ReadMe.txt in the "TODO's, Notes
and known issues" section:

3. The driver will not work with the original drive attached. to fix
this, either remove the "group" parameter in the service entry in the
registry of the driver on which the disk is attached (for atapi this is
done on installing the AoE driver, for SATA, SCSI and others, search the
correct service), or zero out the MBR of the drive.

- You missed the second bullet on the HowTo guide[1]:

Unplug the disk containing the operating system image, and attach it to
the SAN target
 machine.

- You started changing things (drive letters) while things weren't right

When you originally booted and saw F:, it's a toss-up as to which disk
(local versus SAN) you were actually booted from, regardless that you
definitely used the SAN to _begin_ the boot process.  This is because
Windows looks at a signature in the MBR for each disk and compares
against what was saved earlier in the boot process from Windows'
boot-loader (NTLDR or whatever).

Try seeing if you can boot the local HDD without any gPXE or SAN action.
If you can, make a note of what drive letter you get for the system
volume.  If you really wish to repair, please report your findings.  It
might be easier to start again, keeping the above mistakes in mind.

- Shao Miller

A few emails later Shao Miller wrote:

The most important part of all of this is making sure that no two disks

attached to Windows at the same time have the same disk signature in the

MBR.



Also, even if a tool changes one of the disk signatures, Windows has a

record in the Registry at the HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices\

key which maps the drive letters to the disk signatures.  It might even

be a good idea to delete those entries _if_ you are going to dare to

boot from SAN the very first time with more than one disk attached.

Once you've booted the SAN with just the SAN attached, Windows should

overwrite any existing record with the proper information.  After that

you can feel free to add as many disks as you like, as long as no two

disks share a disk signature.



      
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