FBA RAM consumption

[Günter Wirth]

Hello,

How much RAM does EWF need, to write protected a Compact Flash.

Example:
If I use a Compact Flash with 128MB, with activated EWF,
does this consume also 128MB RAM?

Regards,
Günter

 

[KM]

Günter,

The EWF RAM usage would depend on how you structured the image, what
components/logon/shell included, how they work.
With a proper image setup (you remove or move to an unptotected partition
most of the logs, user data, etc.) you can lower EWF usage very much.
With a minlogon image < ~60M, I have had the EWF "normal" usage not exceeded
1-2Mb. Although, I have not stress-tested the device that time.

Also, read this great tip:
http://msdn.microsoft.com/embedded/community/community/tips/xp/ramewf/default.aspx

KM

 

[Günter Wirth]

KM,

That means: I need normally alway more RAM than I try to protect with the
EWF manager.

If I try to install my Windows completly on a compact flash (with about 800
MB), I need normally more than that 800 MB RAM to get never a write error
message.

My idea was no to check the amount of memory which is used by EWF an
generate automatically a 'Commit' to free the memory. The problem is that
EWF frees the memory only after a reboot.

Has anybody an other ideas to protect e.g. a 2GB compact flash with EWF and
only 512MB RAM?

Regards,
Günter

 

[Slobodan Brcin \(eMVP\)]

Hi Gunter,

You understood Konstantins reply incorrectly.
If you make your image with great care RAM EWF should not consume more that few MB.

Look at thread above that Carl asked.

Best regards,
Slobodan

 

[Günter Wirth]

Hi Slobodan,

You are right, but:
If I use Windows XP Embedded as a substitute for Windows Professional and if
I need a CF because a HD is to sensitive, then I run into problems.

We like to sell the hardware + Windows on a CF and our customer should be
able to install software onto the device => the CF should work like a HD.

If I use the EWF manager it is possible the computer runs out of memory
after running for a longer time. That was the reason I tried the solution
with the 'Commit' before low memory appears.

Why do I have to reboot the system to write the EWF buffered data to CF?

Regards,
Günter

 

[Slobodan Brcin \(eMVP\)]

Hi Gunter,

Why do I have to reboot the system to write the EWF buffered data to CF?

This option is probably introduced to work this way since during the shutdown it is only point in time that FS is closed and all
data is flushed in RAM overlay, so EWF can write 100% coherent data to disk.

In SP2 there should be a change to EWF that will allow you to commitanddisable overlay in flight or something like that. Doing this
before huge installations will solve your problems. For now you can either tell user to disable EWF reboot and then install things,
then enable EWF and reboot again :-(
Or you can use disk overlay but this is probably not what you want.

Best regards,
Slobodan

PS: I really don't have any smart idea for your case, since usually users should not install applications on their own or if they do
then they should know how to do it by instructions that you will give them.