Seeing in forum as pointed
https://productforums.google.com/forum/#!topic/chromebook-central/vO9dA6qIVqw

I don't think the details usage list is meant to be an exhaustive list.

#2 I understand that the usage list may not have been intended to be an exhaustive list. But, what is missing? If the details of the missing usage can't easily be determined, perhaps a simple note "Usage details do not include _____".

That would at least help users understand what they should look at to clear storage.

Right. The list is not intended to be exhaustive, and it includes only several storage types which can consume multiple gigabytes and users can manage the usage.

The biggest consumer in missing part is Chrome OS system files, but we also ignore many other types (e.g. Chrome extension files, which are ignored as they should be smaller).
Explaining the missing parts exhaustively will be lengthy.

mitsuji@, do you think we should add some explanation about missing parts?

Please consider that in the example shown, around half of the used storage is not included in the list. That is what makes the numbers so confusing to users.

Perhaps we could add another section (i.e. other, system files) to reflect the gap. Users won't be able to manage it but could message to them if they try to click on it. 

#8 - That could work. Non-technical users should be able to see that they have a 16/32/64 GB drive, see that ___GB are used by OS and system files that they can't do anything about, and ___GB used by things that they could manage if they need to free up space.

fukino@ can we do this from a technical perspective? 

It is easy to add one "Others" section and just show the size which is ({total usage} - {sum of existing sections})

Showing "system files" will need some investigation.
* We need to make the definition of "system files" clear. Maybe the files outside user's cryptohome are "system files"?
* Keeping track of the size of system files will be time consuming. We won't be able to update it frequently.
* {system files} + {sum of existing sections} still doesn't match the total used size. We need "others" section anyway to match the sum of sections to total size. 

I'm leaning towards a simple solution by lumping everything into 'other' with an icon that displays a carrot with more info. The carrot could provide copy to the user on what it includes (i.e. system files) but remains inaction-able.

Something similar to a managed device user who goes to settings/privacy and security/protect you and your device from dangerous sites/hover over icon on right.

Here is a great example of the confusion and incomplete information faced by a user on CBC. He has documented the situation quite well with screenshots showing storage was full. Around 12 GB was used by some unknown files.

Deleting extensions seemed to have cleared out most of whatever was using up his storage. I will try to get details, but I can't imagine 12 GB of extensions, so could the extensions be saving files that aren't showing up properly?

Other than deleting the extensions, how could the user recover the space?

The total "In use" now almost matches the itemized usage details.

https://productforums.google.com/forum/#!topic/chromebook-central/vKUcbZ40Nsc

(Bulk Edit) Adding the new conops Chrome OS hotlist to all open issues with the "#CBC-RS/TC-watchlist" tag, our former tracking tag.