Windows Installer supported compression

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Joined: Sun Nov 08, 2020 9:05 pm

Windows Installer supported compression

Post by Pigmaster »

Hi All

I build a custom windows 10 installer via sysprep (windows 10 pro Build 20H2). The windows created wim-file is too large to my liking, over 9gb (want it to fit on a 8gb drive). Therefor I was trying to use wimlib to recompress the file and inject in into my windows installer.

As I wanted to use secure-boot without creating a separate partition on my drive. So as the partition need to be fat32 therefor the intend is to compress and split.

Testing the original wim-file, the installer completes without any issues.

Not knowing if LZMS solid is allow to be split, I tried this without success. Compression worked like a charm, shronk to 5.6gb.

Code: Select all

winoptimize.cmd install.wim --solid
RENAME install.wim install.esd
Trying to split the file to make it fit on a fat32 windows fails to run the installer.

Code: Select all

wimsplit.cmd install.esd install.swm 1000
Thinking that many only a wim file could be split, my next test was to use the non solid LZX, but getting the same error.
As expected the compression is a bit less, but should still fit a 8gb drive

Code: Select all

winoptimize.cmd install.wim --compress=LZX:100 --chunk-size=2M
wimsplit.cmd install.wim install.swm 1000
Does anyone know if there is a way to split a esd file? Or is this only possible with a wim-file?
And what the maximum supported chunk-size is for LZX within the windows installer?

Thanks in advance

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Joined: Sun Aug 02, 2015 10:31 pm

Re: Windows Installer supported compression

Post by synchronicity »

wimlib doesn't support splitting solid WIMs, a.k.a. ESD files.

Microsoft's software doesn't support LZX chunk sizes other than 32k. The support for LZX chunks up to 2M is a wimlib-specific feature. (At least, last I checked. It's been a few years since I last checked this.)

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