HD faults protection using EWF

  • Thread starter Thread starter Guest
  • Start date Start date
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Guest

Hi guys.
I would like to know if it's possible to use XPe w/ EWF as a solution to HD
faults, not only from power blackouts (an UPS will be enough) but also from
making-a-mess users.
What I'm thinking to is a mechanism that would work in this way:
I have my main hard drive with full working and configured operating system,
drivers, applications on it; let's call it the "original configuration".
I put an overlay that redirects all writes/reads to a second (physical) hard
drive; all the software must continue to think it's still using the main HD.
If a user makes a mess or a during-a-write blackout brings to and "HD
failure", I would be able to remove the overlay and use (just) the main hard
drive, i.e. what I called the original configuration.
Also, if I need to update the original configuration, I can remove the
overlay, choose if accept modifications which are on the overlay itself,
remove the overlay, make needed adjustments obtaining a new configuration
which would protect by a (new) overlay.

Am I asking too much?

Thanks in advance for your comments,
Enzo
 
Hi Enzo,

No, you are not asking too much. You can use EWF based on disk overlay for this.
You can create as many layers as you need but in your case one will be enough.

If you want to create EWF partition on same physical disk then you can use any EWF.
If you want second physical disk for this purpose them you will have to use EWF from XPe SP2.

Regards,
Slobodan
 
Thanks a lot Slobodan.

Hope you know it: does SP2 EWF will be released in next months (into the XPe
SP2)?

What if the second HD containing the disk overlay data will break? Will EWF
re-direct all read/write to original HD *AUTOMATICALLY* ?

Regards,
Enzo
 
Hi Enzo,
What if the second HD containing the disk overlay data will break? Will EWF
re-direct all read/write to original HD *AUTOMATICALLY* ?
Click to expand...

Depending of what you mean by break.

1. Data corruption.
In this case user can use F8 option while ntldr. is starting and he will have a choice to discard all data from overlay, meaning
that during the boot original data will be used, but overlay will still protect all writes and redirect them to now empty overlay.

2. Disk failure.
In this case EWF fallbacks to registry configured settings. Here you can define either RAM overlay settings, or leave EWF disabled.
In second case it will be as if you did not included EWF at all. All writes will be done to XPe partition.
Hope you know it: does SP2 EWF will be released in next months (into the XPe
SP2)?
Click to expand...

Download XPe SP2 Technical Preview, it might be there already. I guess that I will do that today, yesterday I had some firewall
problems to access update.

http://msdn.microsoft.com/embedded/...future/techpreview/xptechpreview/default.aspx

Best regards,
Slobodan
 
Hi Enzo,
here is "nearly" everything about EWF:
http://msdn.microsoft.com/library/d...-us/xpehelp/html/xeconEnhancedWriteFilter.asp

You are also able to control the EWF-Layers (up to 9 layers) by your own
software by using the EWF-API.

Regards,
Sören

http://msdn.microsoft.com/library/d...-us/xpehelp/html/xeconEnhancedWriteFilter.asp

Slobodan Brcin (eMVP) said:
Hi Enzo,


Depending of what you mean by break.

1. Data corruption.
In this case user can use F8 option while ntldr. is starting and he will
Click to expand...
have a choice to discard all data from overlay, meaning
that during the boot original data will be used, but overlay will still
Click to expand...
protect all writes and redirect them to now empty overlay.
2. Disk failure.
In this case EWF fallbacks to registry configured settings. Here you can
Click to expand...
define either RAM overlay settings, or leave EWF disabled.
In second case it will be as if you did not included EWF at all. All
Click to expand...
writes will be done to XPe partition.
Download XPe SP2 Technical Preview, it might be there already. I guess
Click to expand...
that I will do that today, yesterday I had some firewall
 
Thank you guys for hints.

Since I'm new to XP Embedded (well, I'm new to the whole embedded
environment) I'm collecting software & documentation to start my tests.

Glad to know that someone will promptly help me if I get into troubles.
 
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