So my question is: how to validate/verify the layout for an offline situation while ensuring that no network connection will be necessary in the offline installation scenario (i.e. at least --noweb)?

NB: to be certain I also like to turn off network anyway while validating (from within a VM), but the idea behind --noweb appears to be that.

Background

I prefer to create an offline installation for Visual Studio, which combines the different editions in one .iso (UDF) file. It works generally nicely thanks to the duplication across editions which mkisofs can deduplicate via -duplicates-once; and packers will be able to achieve the same if they know how to handle hardlinks, after a treatment with hardlink or dfhl or similar tools. The resulting .iso for VS 2022 (17.3.6) for example is a mere 36 GiB in size, including the editions: Build Tools ("28 GiB"), Community ("35 GiB"), Professional ("35 GiB") and Enterprise ("35 GiB"). The hardlinking process saves a little over 100 GiB altogether.

Since I typically get at least a handful of of download errors

I used the following commend line:

.\vs_setup.exe --layout C:\Demo --verify --noweb --lang en-us

CodePudding user response：

Found the underlying issue. As it so happens, mounting an .iso file means it gets mounted read-only. That seems to be the single defining factor here.

Exhibit #1 (my scenario with read-only layout directory):

Yes, I could have left some more seconds or minutes of still image at the end, but take my word there is nothing happening there.

Exhibit #2 (same contents but copied to a writable location)

So to conclude: this appears to be a defect or - euphemistically - an undocumented design decision. It is beyond me why verification/validation of data would require more than read-only access, though.