What are the disp-mgmt vms?

General Discussion
1

I haven’t used the Qubes Update tool for a while, but having just installed 4.1 rc4 I gave it a go, and happy to say it works fine. I don’t remember seeing the popup ‘disp-mgmt- starting’ before though, and I can’t see any ddescriptions in the documents. Can someone explain what they are and what they do?

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2

Those are the disposable updating qubes for your templates whenever they have some sort of updates.

3

I guess they’re only used by the updater, not when you update templates directly using apt or dnf?

4

It’s only used by the updater.

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5

Thanks

6

The Update tool uses salt to manage updates of the templates.
The disp-mgmt- qubes that you see are used as intermediaries between
dom0 and the target template - salt configuration is copied from dom0 to the
disposable and then salt-ssh is started from the disposable to send
instructions to the template.
This means that dom0 does not interact directly with the template.

The management disposables do not do any updating - the templates update
as normal, using the update proxy.
The Management disposables simply pass configuration and instructions to
the templates.

Updating is just one example of using salt. You can read more here
Whenever you use salt, configuration and instructions are passed via these management
disposables.
This actually isn’t a new feature.

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7

Thanks for the explanation @unman. Makes sense to me now. Maybe a para in the docs specifically referencing ‘disp-mgmt’ together with an explantion like the one you’ve just given would help people find it?