Confusing UI - "Use secure erase" and "Use quick erase" are supposed to be subsidiary of "Erase nodes' disk"

[Nobuto Murata]

maas: 1:3.3.0-13159-g.1c22f7beb-0ubuntu1~22.04.1
maas-ui: 3.3.0 acde9f13b45dd515b3d9638545bf82d282d7d5a2

In WebUI as MAAS/r/settings/storage, there is disk erase related configurations.

1. Erase nodes' disks prior to releasing (True/False)
2. Use secure erase by default when erasing disks (True/False)
3. Use quick erase by default when erasing disks (True/False)

Those 3 are presented equally at the same UI level in the WebUI. However,

2&3 do not take effect unless 1 is True, so it would be nice if
- 2&3 are grayed out if 1 is False.
- 2&3 are displayed at a subsidiary level of 1 in the UI (indented for example)

2&3 are mutually exclusive by design and MAAS doesn't not allow to release a node if both 2&3 are enabled so it would be nice if
- the fact that 2&3 are mutually exclusive is reflected in the UI (radio box or something)

[Nobuto Murata (nobuto)]

> 2&3 are mutually exclusive by design and MAAS doesn't not allow to release a node if both 2&3 are enabled

I have a second thought on this. API operations actually allows both to be set. And the API client's help explains the behavior at least from a documentation point of view.

$ maas admin machine release -h
...
> If both ``secure_erase`` and ``quick_erase`` are specified and the
> drive does NOT have a secure erase feature, MAAS will behave as if only
> ``quick_erase`` was specified.

So the mutually-exclusive behavior itself can be the bug in the UI.

[Thorsten Merten (thorsten-merten)]

We should indent the second and third option and make it disabled unless the first option is checked.
Also the second and third options should be radios as they are mutually exclusive.

[Nick De Villiers (nickdv99)]

Closing this as "Won't fix", following discussions with the team.

Any combination of options is technically valid, as explained below:

000 : Disks are not erased automatically when releasing. If erase is specified it will be slow (writing null bytes to the whole disk)
001: Disks are not erased automatically when releasing. If erase is specified it will be quick (using wipefs)
010: Disks are not erased automatically when releasing. If erase is specified it will use the secure erase feature of the disks if present, else fall back on slow writing null bytes to the disks
011: Disks are not erased automatically when releasing. If erase is specified it will use the secure erase feature of the disks if present, else fall back on using wipefs

100: Disks are erased automatically when releasing.
101: Disks are erased automatically when releasing. It will be quick (using wipefs)
110: Disks are erased automatically when releasing. It will use the secure erase feature of the disks if present, else fall back on slowly writing null bytes to the disks
111: Disks are erased automatically when releasing. It will use the secure erase feature of the disks if present, else fall back on using wipefs

[Nobuto Murata (nobuto)]

I'm confused by the decision.

As you precisely described, the first digit makes a huge difference and has the highest priority in the outcome. I don't disagree on that any combination is technically possible, but the UI is confusing people as of today since the "If erase is specified" part is not reflected in it so there is no clue unless one reads everything in the help of MAAS CLI.

My ask to the MAAS UI is to be less confusing so I thought it was a low hanging fruit such as:

> 2&3 do not take effect unless 1 is True, so it would be nice if
> (...)
> - 2&3 are displayed at a subsidiary level of 1 in the UI (indented for example)

[Thorsten Merten (thorsten-merten)]

Hi Nabuto,

we just discussed this in the team. If we understand your comment correctly, you are missing an explanation of that will happen especially in the cases:

X00 case (slow writing disk either on release or when deleting manually) and
X11 case (trying secure erase but falling back on wipeFS in case this does not work)

As these two things are not explained in the UI. We are not sure if indenting would help, but we'll try to find solutions to make this clearer (such as tooltips or explanation sections). Essentially we'll challenge the UX to have a more concise representation of the result of the selection.
However, it does not feel like this breaks MAAS so I changed it to low/3.5 as target.

[Maximilian Blazek (maximilian-blazek)]

The following would be my proposal for hopefully making the UI more understandable. Note that the fallback option for secure erase would only be shown if secure erase is selected.