HORM vs Normal Hibernation ( when needs to write to an unprotectedpartition)

[Shiju]

Hi,
I am trying out HORM feature on windows XPE. I am experimenting a
situation were I have two partitions - one protected with ewf and other
not protected since I have to write data on to unprotected partition. I
follow the steps mentioned in the msdn to lock and unmount the
unprotected partition and then hibernate to protect the data on the
unprotected partition. On resuming I unlock the partition.
My question is in this scenario every time I need to do the process of
lock->unmount->hibernate->unlock.That is every time I have to do
hibernation not just once. This is same as the hibernation on windows XP
except for protection of a partition with ewf. This contradicts to HORM,
which states, you hibernate only once and use the same hibernation file
to resume the system many times. Am I missing something or my
understanding regarding HORM is wrong. Is it possible to hibernate just
once (lock->unmount->hibernate->unlock) and protect the unprotected
partition??

Thanks,
Shiju

 

[Slobodan Brcin \(eMVP\)]

Shiju,

Basicaly you need to make aplication that will internaly do:
1. Lock/unmount FS on all non OS partitions.
2. Hibernate.
3. Terminate (this will do auto unlock).

By doing this OS will not be aware of existence of filesystem and files on
it. So you can write what ever you want and when you resume you will have
new data ready to use.

Regards,
Slobodan

 

[Shiju]

Hi Slobodan,
This means each and every time when I need to bring the system down, I
need to do the below three steps that you mention.

And regarding step 3, did you mean that there need not be an application
to unlock the locked and unmounted partition once the system is resumed
from hibernation. Does the unlocking happens automatically when the
system resumes.

Thanks,
Shiju

 

[Slobodan Brcin \(eMVP\)]

Hi Shiju,

This means each and every time when I need to bring the system down, I
need to do the below three steps that you mention.

No. Quite opposite.

I guess that my thoughts are distracted so I did not gave you clear answer.
You do that steps only once.
Step 3 will be always executed at each resume. And you should stop worrying
about this since it will work as you want it to.

And regarding step 3, did you mean that there need not be an application
to unlock the locked and unmounted partition once the system is resumed
from hibernation. Does the unlocking happens automatically when the system
resumes.

It is good practice to reverse operations always. But this operation is
automaticaly reversed when you aplication terminates or when you close
handle to locked volume.
One more thing you do not unmount partition, you unmount filesystem and stop
FS driver for that partition.

When system resumes your appliacation will always execute from point after
resume command. So when your application terminate partition will be
unlocked.

FileSystem will be loaded first time that you try to access some data from
it.

Regards,
Slobodan

 

[Shiju]

Hi Slobodan,
Thanks. I think I did not make my system setup clear. I have two
partitions on my system. One is the windows XPE OS partition and the
other is a data partition or windows XP pro( in case it is a dual boot
system). I allow applications on windows XPE to write to the other
partitions. It can be assumed that every time the windows XPE OS is
running the applications will write to the other unprotected
partition(ewf(RAM Reg.) is enabled only for windows XPE partition). So
in this scenario I may have to do lock->unmount FS->hibernate->unlock
each and every time the system is shutdown(hibernate in HORM). Am I wrong ?

Thanks,

 

[Slobodan Brcin \(eMVP\)]

Shiju,

When dealing with hibernation, you must forget about dual-booting or
changing data from bootable CD. This can't be safely done.

You application data usage is quite normal. HORM Hibernate Once Resume Many
as MS called it can be used as that .
As long as you have all FS covered by EWF this will work.

By unmouing FS you effectively remove it from OS region of interest. So when
you hibernate for the first time it will be as if you had only FS with OS on
it present.
You can do what ever you like with data on partition that is unmounted
before the hibernation. You could even change FS type and OS would not care.
First time when you access this partition FS would be loaded and seen by OS
again.


So if you talk about HORM you will need to hibernate only once, and never
again unless you want to disable HORM.

Regards,
Slobodan
PS:
Read about some of this from this thread:
http://groups-beta.google.com/group...onstantin+Hibernation&rnum=1#b50c664acc022687