boot from a file backed wim
#1
Posted 13 March 2011 - 03:17 PM
Idealy, i would like to have a dual boot option, .wim in RAM and wim on CDVD/USB-Stick/HDD.
So far, i havn't found a wim script in any project, which offers such a feature.
Is this because it can't be done or because nobody was yet interested in it?
#2
Posted 13 March 2011 - 04:05 PM
#3
Posted 13 March 2011 - 04:31 PM
A setup like that is possible with hdd-images.
But i have too little knowledge about Vista/Win7, to know, if it can be done with .wim too.
#4
Posted 13 March 2011 - 04:43 PM
The hdd-images (images on HDD) are expanding to RAM just like WIM on CD expands to RAM. The WIM must expand to be bootable.The wim should expand to nowhere. It should be used right from the drive.
A setup like that is possible with hdd-images.
#5
Posted 13 March 2011 - 04:55 PM
But one can also use a hdd-image(image of a hdd) straight from a CDVD, without loading it into RAM first.
#6
Posted 13 March 2011 - 05:07 PM
A WIM image? Not as far as I know but...But one can also use a hdd-image(image of a hdd) straight from a CDVD, without loading it into RAM first.
#7
Posted 13 March 2011 - 05:15 PM
#8
Posted 13 March 2011 - 05:19 PM
Deja vu?I don't know, if it can be done with a .wim image, that's why i ask...
I'm sure that Jaclaz will have explained at the time that part of the reason is because WIM images lack a bootable filesystem. That's why a ramdisk needs to be created, the contents of the WIM loaded onto it, and then the ramdisk booted.
Regards,
Galapo.
WIM images need to be deployed to an existing volume or partition as the toolset does not create low-level disk structures such as partitions, nor does it format them.
http://en.wikipedia...._Imaging_Format
#9
Posted 13 March 2011 - 05:41 PM
I'm pretty sure, that's not the way it works.I'm sure that Jaclaz will have explained at the time that part of the reason is because WIM images lack a bootable filesystem. That's why a ramdisk needs to be created, the contents of the WIM loaded onto it, and then the ramdisk booted.
Regards,
Galapo.
Else booting a .wim into RAM and booting a .img into RAM, which contain the same files, would require the same amount of ram. But one of the advantages of .wim over traditional .img is the better compression.
If i'm wrong and you're right, this whole question would become immediately pointless.
#10
Posted 13 March 2011 - 05:46 PM
but according to some of my chinese friends , a wim based image is MORE efficient on low ram systems then ANY OTHER format like .IMG etc .
#11
Posted 14 March 2011 - 12:05 AM
It behaves more like ImDisk and not like M$ramdisk.sys.
Since i see no reason, why M$ should throw away it's own ramdisk driver, to get one, which works differently, but serves the same purpose. I don't think that a ramdisk is first created and then the .wim file loaded onto it.
Besides, shouldn't get such a ramdisk a own drive letter?
Also extracting the contents of the .wim file to the ramdisk is out of the question. This would increase the required space for the files, which is just not consistent with comparisons between a SDI-booted PE and a wim-booted PE.
#12
Posted 14 March 2011 - 12:35 AM
#13
Posted 14 March 2011 - 12:45 AM
Bcdedit –store E:\boot\BCD –set <GUID> osdevice boot Bcdedit –store E:\boot\BCD –set <GUID> device boot
Just an idea, may serve the purpose and worth a little digging, although not quite sure what the real gain in terms of RAM usage would be, plus if booting from USB the necessary changes for the USB drivers should be made.
Added: Rereading topic title, the above written seems well off topic.
#14
Posted 14 March 2011 - 04:59 PM
Manufactuer describes How Booting into a Boot Image WorksI don't think that a ramdisk is first created and then the .wim file loaded onto it.
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