EWF and CF Drives.

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Guest

Hey guys, this is more a design question than anything.

We are using our PCs in an industrial enviornment, and so we decided to use
CF drives. There has been a request that the CF drives have a "Read Only"
feature so that we can preserve the CF drive for as long as possible. I
still don't fully understand EWF so I'm gonna ask the pros.....I'm not sure
if I would need EWF if I somehow switched the drive to read only?

Does anyone know of a generic solution for flash drives that I can switch it
to read only?


Thanks, as ususal for all your help
 
Hi Mark,

If you switch firmware to read-only or write-protected mode then OS won't be able to write changes during the boot and your system
will hang.
RAM EWF is required (non-optional) with above scenario. So all changes will go to RAM overlay and system will boot.
I think that this behavior is described in documentation under El-torito CD boot. Same thing are true for all read-only mediums (you
must have RAM EWF).
Does anyone know of a generic solution for flash drives that I can switch it to read only?
Click to expand...
I do not think that there is any generic solution available it is more manufacturer proprietary option.

M-Systems uDOC devices have an option that allow you to switch firmware to Write-Protected mode trough software utility or their
SDK.
You can even tell uDOC firmware to behave as two separate disks (trough utility you set size of first disk). And you can protect
first disk with OS-on it from any further modifications.
While second disk is still available for any use that you want.

Regards,
Slobodan
 
Order this book if you want more understanding of EWF:
Windows XP Embedded Advanced
Available from Amazon.com
 
Hi Slobodan,

Have you used the binary partition of the DOC with XPe? I just
found out about that feature this week and was wondering how one would
use it with XPe. I've seen info for CE and Linux but have yet to come
across anything for XPe. I plan to experiment with the binary
partition next week but if anyone has some helpful hints that would be
great.

Would using the binary partition be better than using EWF? Does anyone
know of a Pro/Cons list comparing the two?

Thanks
 
Hi Dwayne,

Don't know much on "Binary partition" feature of DOC devices, but uDOC have similar option made exclusively for XPe.
You can split uDOC to two logical disks (each up to 4 MBR primary partition). And disk with XPe can be protected from further writes
by security key.

Anyhow, when disk write protection is on you must use RAM EWF to prevent OS write accesses from reaching WP disk.

Other solution that you probably can use with DOC "Binary partition" is to use RAM boot from SDI file. (No need for EWF but you will
need allot of RAM)

Regards,
Slobodan
 
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