Linux 6.7 Adding New Feature To Btrfs For The Steam Deck

[zilexa]

Can anyone explain to me why Valve does not go for an immutable OS for the Steam Deck?
Or am I confused and is that exactly what they want to do with A/B partitioning?

[EphemeralEft]

It's all about reliability. SteamOS is installed twice, because if one filesystem goes down, the other can still work, therefore the device can heal itself without user even noticing. Sub-volumes won't do that as they're basically directories with extra steps that you can mount as individual filesystems among other features, but in fact they all sit in a single BTRFS instance.

Valve is probably working on the assumption that snapshotted subvolumes share most of their physical extents; if the area on the disk holding shared extents became corrupted, then all references to those extents (i.e. both subvolumes) would be damaged.

But that’s not always how BTRFS functions: you can specify the double meta/data profile, which stores 2 separate copies of everything on the same file system. That has the added benefit that, should such a corruption occur, the other copy will automatically be used for both subvolumes. Also, it would allow you to have as many copies as you want.

If they’re concerned that different “locations” on an SSD may actually correspond to the same physical location, they should know that different partitions on the same disk have that same issue.

[EphemeralEft]

Although I think this feature is unnecessary for Valve (see my earlier comment), this will be a really nice feature for LVM snapshots. Previously you’d have to change the UUID on all snapshots, which made restoring from them more difficult.

[darkbasic]

Once ZFS gets reflink support

It's already in 2.2 which is in rc4: https://github.com/openzfs/zfs/issues/405

[sbivol]

A question: their Steam Deck can be used as a desktop computer?

With Linux? No, it can't. Valve only published Windows drivers, all Linux distros have virtually no access to SteamOS specific code.
To give you an example: sound doesn't work on Linux. A guy contributed ALSA UCM configuration this year so future distro releases can incorporate it, but Valve couldn't be bothered.
Another one: power profiles can't be adjusted.
Display backlight can't be turned off. The joystick doesn't work. They haven't contributed their maliit-keyboard skin, nor the most of their other keyboard improvements. SecureBoot can't be enabled because no platform keys are provisioned.

To put this in perspective, the Microsoft Surface Go laptop has none of those issues on Linux, it even provides a firmware virtual keyboard to use for entering the disk decryption (even though the device itself still has a physical keyboard). Steam Deck has no firmware-based keyboard, you need to attach a USB keyboard to decrypt disks during boot.

My Deck also has this bug where the internal disk simply disappears if you power it on with a dock attached. Even the BIOS can't detect it. This happened on first boot out of the box and I almost returned it before I tried starting it without the dock.

[Quackdoc]

With Linux? No, it can't. Valve only published Windows drivers, all Linux distros have virtually no access to SteamOS specific code.
To give you an example: sound doesn't work on Linux. A guy contributed ALSA UCM configuration this year so future distro releases can incorporate it, but Valve couldn't be bothered.
Another one: power profiles can't be adjusted.
Display backlight can't be turned off. The joystick doesn't work. They haven't contributed their maliit-keyboard skin, nor the most of their other keyboard improvements. SecureBoot can't be enabled because no platform keys are provisioned.

To put this in perspective, the Microsoft Surface Go laptop has none of those issues on Linux, it even provides a firmware virtual keyboard to use for entering the disk decryption (even though the device itself still has a physical keyboard). Steam Deck has no firmware-based keyboard, you need to attach a USB keyboard to decrypt disks during boot.

My Deck also has this bug where the internal disk simply disappears if you power it on with a dock attached. Even the BIOS can't detect it. This happened on first boot out of the box and I almost returned it before I tried starting it without the dock.

they have absolutely released their kernel source code,

for everyone else reading with half a brain who wants to skip googling. instead of listening to this guy's BS, if you want the linux drivers and steamOS specific code, it can all be found here

https://steamdeck-packages.steamos.cloud/archlinux-mirror/sources/

[sbivol]

https://steamdeck-packages.steamos.c...irror/sources/

Released? Sure. To their own repo.
How many of those are contributed upstream?

[Quackdoc]

Released? Sure. To their own repo.
How many of those are contributed upstream?

They have contributed a good chunk of it upstream, kernel 6.1 has pretty good oob support for steamdeck, sound has worked since kernel 6.0.1. Power profiles I don't care about so I have no idea. controller is being added for 6.3. not sure what they need to upstream for maliit, tbf I dont really care about skin support, and secureboot is another thing I dont care about

[pepoluan]

Released? Sure. To their own repo.
How many of those are contributed upstream?

The movement of goalposts is so visible here.