Tuesday, August 24, 2004

Remote Boot deployment issues

I've been working on an issue for two different customers who are trying to use Remote Boot Server (RBS) as a deployment tool.  The scenario goes like this - build a remote boot image, boot a device using that RBS image, then copy a different image from your network to the underlying media on the device.  The steps for building the RBS SDI include booting the device through FBA, then cloning the image using FBReseal.  After the cloning, you build an SDI from that golden master image to capture the image ready for remote booting.

The problem occurs when the media you built the RBS SDI on differs from the underlying media now in the machine.  For example, if you built the RBS SDI on a 256 Mb flash card, but the device you're booting now has a 128Mb flash card, you cannot see or access the 128Mb flash.  This is a known issue for us - we have a bug on it.

The good news is there is a workaround for this issue (which is 99% of the way to resolving the issue for one customer).  Creating the RBS SDI is a two step process - copy the golden master image to a partition in an SDI file, then read that partition into a second SDI file that becomes the remote boot image.  Before you create that final SDI, but after the image has been cloned, you need to delete the following registry key:

HKLM\SYSTEM\ControlSet001\Control\CriticalDeviceDatabase\gendisk

This key is created during FBA and is tied to the underlying media.  Because the media is changing between the time of cloning and the time of booting, there is no longer a connection between the two, so if the media changes, the connection is lost and you can't see the media anymore.  By removing this registry key, PnP will detect the underlying media, recreate the key, and make the link between the two.  Viola!  Now you can see the underlying media (usually as drive D:, since the RAM disk is drive C:).

No need to thank me - that's what I'm here for.  Well, that and the free soda...

1 comment:

rs said...

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