Update existing Windows 8.1 WIMBOOT wim image?

[supercilious]

Hi,

I have an existing Windows 8.1 Pro installation that was deployed using wimboot. The wimlib documentation is not clear about this, but can I capture the installation as a new wim image? The current installation is a mix of wim pointer files and "real" files as installation is already quite old and many windows updates and various other changes have been made since. I would like to capture the installation as a WIM image and use that image to deploy a fresh wimboot installation so that without data-loss I can recover around 30GB of space on my tiny tablet's (non-upgradeable) 64GB SSD.

Thanks

[synchronicity]

Yes, that is possible. You'll need to capture a new WIM file containing the main partition; then reformat the main partition and apply the image from the WIM file with the --wimboot flag.

For improved space savings, you could use LZX compression (capture with --compress=lzx).

[supercilious]

Wow, despite over a year of updates, the new WIM is only 200MB larger than the previous one. LZX compression makes a hell of a difference, and does not appear any worse performance wise on this machine (Bay-trail Celeron N2910). This is amazing!

Can I use other (larger) block sizes too? or does the Windows WOF driver not support those?

Thanks for this awesome library and associated tools

[synchronicity]

The WOF driver does not support any LZX chunk sizes other than the default (32768 bytes).

wimlib does allow you to set a higher compression level while retaining the same chunk size (e.g. using --compress=lzx:100), but this typically improves the compression ratio by less than 1%.