Relocating EWF disk partition

[David Harris]

Does anyone know if it is possible to relocate the partition used by disk-based
EWF onto a specific drive (e.g. not the boot device).

I have a system with a CF card (the boot media) and a HDD. I want to boot from
the Compact Flash (to make updates easy), but have persistent changes allowed
while protecting the CF. As the units may be subjected to removal of power by
unplugging it would be simplest to store the persistent EWF data partition on
the HDD.

David

 

[John Coyne \(eMVP\)]

David,

Kind of confusing post... in one sentance you say that you want to boot from
CF, but have persistent changes allowed (which you can do to a point if it's
data and such), an dthen you say you want the EWF Partition on the HDD...

The simplest way to do this is build the image on CF, protecting CF with EWF
and then you can store data on the HDD, so that it will persist. if you are
wanting to persist the OS Registry and such and use EWF, you can persist
some things with EWFMGR... be careful, though.

Here's some pretty good documentation on EWF and what can be done with it,
as well as how to have apps interact with it.
http://msdn.microsoft.com/library/d...-us/xpehelp/html/xeconenhancedwritefilter.asp

HTH,
JC

--
John Coyne
eMVP
Windows Embedded Black Belt
Arrow Electronics, OCS division



When replying directly to this message remove the NOSPAM_ from the address

 

[David Harris]

Sorry for the confusion, I tried to summarise everything and probably left too
much out.

The systems are standalone and not networked. All data transfers use RS232
connections.

They are fitted with CF and a HDD. They will boot from the CF to make major o/s
& application updates easy to perform.

The units will run 24/7 for up to a few weeks at a time between reboots. But
they may be turned off (or the power disconnected) without prior notice by
unskilled staff.

The applications running on the systems are heavy users of memory and constantly
update large data and log files. It is very important that the data and log
file contents are persistent even if power is removed without notice.

Systems will use EWF to provide a fail-safe in case of system corruption or
misuse. This will be for both the HDD and
the CF, and skilled local staff must be able to restore default system operation
within 5 minutes without needing access to outside help (reset EWF or install a
new CF).

Administrator users will be able to install minor o/s or application updates
onto the system. Then commit those changes to be the system defaults once
correct operation has been verified.

From the above you can see that using RAM-based EWF would need LARGE amounts of
extra memory given the up-times expected. Using disk-based EWF makes more sense
but the system expects an EWF partition on the boot drive (the CF, not a good
idea).
I looked at the EWFAPI structures and it does not seem possible to be able to
put the disk-based EWF data partition anywhere other than on the boot drive.
I tried to combine RAMREG-based EWF (for the CF) and disk-based (for the HDD)
but XPe still wants to create an EWF partition on the CF.
Given the above I surmised that it was not possible to move the EWF disk
partition off the boot drive, but wanted confirmation of that fact from the
experts (your good selves)

David