Remote Boot Problem - RAM Disk Limitations (MS Issue)

  • Thread starter Thread starter Craig
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Craig

So, I've managed to get Remote Boot running with a test image ... not a
problem, but there's a question about image size limitations. This could be
an issue because my deliverable image is currently 900 MB and could grow to
1.5 GB or more and we have a requirement that a network boot is an available
option. My understanding was the rule-of-thumb was RAM = Image Size X 2.

The Microsoft documentation on Remote Boot inludes 2 considerations:

1. "Verify that the available RAM for the client computer accommodates the
size of the run-time image. Also, verify that the available RAM provides
enough free space for the image to operate once it has been installed."

5. "Verify that your image is 500 MB or less. This includes additional free
space for temporary files, such as Internet Explorer cache files."

Does this mean my image must be "500 MB or less" regardless of the target
RAM? If true, why the arbitrary limitation for the RAM Disk Driver?

Is there a way to work around this limit like 3rd-party drivers?

Thanks,

Craig
 
The RAMDisk itself has a 500 meg limit, so your embedded run-time image
(including buffer) must be 500 meg or less (we've actually seen this fail
anywhere from 500 to 504 meg).

I don't recall why the limit was 500, but I don't believe it was arbitrary.
I will check on it and post an update.

It's interesting that you're planning on deploying a 900-1500 meg image via
remote boot. We've heard from most customers that download and boot time
would make that a non-starter. Since you're the first one I've heard this
request from. I'd like to get more details and, if possible, a full
scenario. Feel free to respond here or in private mail.
 
NTLDR creates the RAMDisk very early in the boot cycle. Because of the way
NTLDR accesses memory RAMDisks larger than 500 meg cannot be created. It is
likely that this will change with the Longhorn Embedded release, but is not
likely to change for XPe service packs.
 
hi ,

Will Longhorn Embedded be faster and more efficient .Would it eat less
of Ram,I Guess it wouldn't .Is the upcommming change going to reflect
in the way the NTLDR is goin to access the memory for initialising the
Ramdisk(can i have a link to it if its there?),(wuld it have more
memory for loading ntldr in for eg remoteboot)
In that case,I guess the boot process hierarchy should change in
Longhorn when compared to XP ..
It would be appreciable if i could get a published link to these
issues if possible .

Thanks
Kesavan
 
I was afraid that it would be an NTLDR issue ... it's unfortunate that there
won't be a QFE to correct the limitation.

Our image is currently about 900 MB ... that includes a relatively
significant MDB file, MSDE and the .NET 1.1 Framework. What is not included
yet is our primary application which will grow the image significantly.

Having to live inside of a 500 MB limitation, we'll probably just create a
post-boot loader that take loads the database, applications and media from
the server. Hopefully, we can fit all of the necessary stuff in less than
500 MB with room to spare ... otherwise "Plan C." This is a better solution
anyway, but I was hoping that Remote Boot (PXE) was a quick-and-dirty way to
an early demonstration of a network boot capability.

Craig
 
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