operating question about power-off

[snarlydwarf]

The SB Touch is running an embedded Linux on ARM processor.
The clean way of "switching off" a Linux system is to do a complete
shutdown, which however takes time, and takes even more time to wake the
system up (reboot) afterwards. You can btw observe this on many BluRay
players who take ages to boot.

No. It has nothing at all to do with Linux.

1) If you turn off a device with a remote, and it is -really- off: how will you turn it back on? It's off: it has no IR sensor waiting for input, no RF sensor waiting for input, no ethernet waiting for 'wake on lan'... it's OFF. You can NOT turn it back on unless you flip a physical switch. There is no way around this.

2) A SB Touch can serve multiple players: if you turn 'off' the Touch in the living room, you won't be able to play music it was serving to the Radio in the Kitchen. It's off. It doesn't do anything when off. People would be very annoyed.

Yet - if all people on earth who have HiFi chains today buy SBTouches and
leave them switched on day and night - can you imagine what the additional
power consumption would be?!?

So - it's not responsible behaviour to leave it switched on - but its not
well designed for being switched off.

Seems there is no easy solution?

You do know that is true for your TV, your Microwave, your PC... unless you PHYSICALLY flip a switch or unplug them, they are on.

(The switch on the FRONT of your PC does not turn it off. You have to use the one on the back.)

Again: if you turn something fully off, you can NOT turn it back on without a physical switch. Period. IR sensors require electricity, as does RF and Wifi and even the touch sensitive panel on the front of your Microwave.

It has nothing to do with Linux: I dare you to just use the big switch on the back of your Windows machine to turn it off at night.

[erland]

2) A SB Touch can serve multiple players: if you turn 'off' the Touch in the living room, you won't be able to play music it was serving to the Radio in the Kitchen. It's off. It doesn't do anything when off. People would be very annoyed.

Are you sure it would annoy people ?

It would definitively annoy people if you needed the Touch to be playing to be able to play music on the Radio in the kitchen but would it annoy them if the Touch would just have to be on ?

What if turning off the Touch would shutdown SBS and unmount the USB drive, but still leave the other parts active. So a user can basically just hit the power button and know that it's safe to disconnect the USB drive afterwards ?

The Touch would still be active but this would make it really easy for non technical users to understand when it's safe to disconnect the USB drive. Also, the Touch would still be alive even though it's built-in server wouldn't, so when you navigate into My Music on the Kitchen Radio it would automatically turn on the Touch, mount the drive and start the built-in server in the Touch.

Wouldn't something like that be easier for people to understand ?

I think it's important that the Touch isn't powered off completely, it has to at least be possible to activate it using a remote or when another player in the house want to play something. But it would probably be acceptable if it went into a low power standby mode where only the necessary parts that was needed to activate it remotely was still turned on.

How does the Touch work when the built-in server is running ? Does it spin down the USB drive as long as no player connected to the Touch is playing music ?

Also, I think the scenarios might be a bit different when the built-in server is used and when someone has an external server running on a computer.

My thoughts are:
1.
It has to be simple how to disconnect a USB drive and we can't expect people to format USB drive with Ext3 as long as Ext3 isn't supported by the Windows formatting tools. It's not a problem if it works better with Ext3 but it has too work good enough with a Windows formatted drive and you shouldn't have to worry about loosing data on the drive.

2.
It's important that any device can go into a low power mode when it isn't used, people worry about power usage for environmental reasons today and we need to consider this if we like to keep living on this planet in the future. There might be other kind of devices that are bigger problems but just ignoring it isn't a good idea.

3.
The Touch might be serving other players, due to this it needs to be possible to turn it on remotely without standing beside the Touch. People that want to play music in their bedroom in the morning doesn't want to be forced to get up and walk into the living room and push a power button on the Touch to be able to start playing music on their Radio in the bedroom.

[snarlydwarf]

Are you sure it would annoy people ?

Yes, I am sure. (Hint: it doesn't have to be 'most' people.)

It would definitively annoy people if you needed the Touch to be playing to be able to play music on the Radio in the kitchen but would it annoy them if the Touch would just have to be on ?

What if turning off the Touch would shutdown SBS and unmount the USB drive, but still leave the other parts active. So a user can basically just hit the power button and know that it's safe to disconnect the USB drive afterwards ?

That's not what the person I replied to asked for: he wanted -conpletely- off. Zero power.

That is plain and simple impossible without a physical switch.

The Touch would still be active but this would make it really easy for non technical users to understand when it's safe to disconnect the USB drive. Also, the Touch would still be alive even though it's built-in server wouldn't, so when you navigate into My Music on the Kitchen Radio it would automatically turn on the Touch, mount the drive and start the built-in server in the Touch.

Then it wouldn't be off, would it? It would at the very least be using WOL, or if wireless, it would be awake with the display off.

that isn't off.

Wouldn't something like that be easier for people to understand ?

That's not off.... and not what was asked for.

My thoughts are:
1.
It has to be simple how to disconnect a USB drive and we can't expect people to format USB drive with Ext3 as long as Ext3 isn't supported by the Windows formatting tools. It's not a problem if it works better with Ext3 but it has too work good enough with a Windows formatted drive and you shouldn't have to worry about loosing data on the drive.

There is a menu option to do just that: turning it into some quasi off state and believing it is then ok to detach a USB drive would lead people to forget that the drive is still being read by some other player...

You would have to bring up a dialog box: "I am not turning off: the Kitchen player is still attached... "

2.
It's important that any device can go into a low power mode when it isn't used, people worry about power usage for environmental reasons today and we need to consider this if we like to keep living on this planet in the future. There might be other kind of devices that are bigger problems but just ignoring it isn't a good idea.

The power difference between on and off on the touch is not significant: the difference is the display power.

Again: to be off, you need a physical switch There is no way around that. A $5 power strip will give you that.

Various 'sleep' modes won't work. (Ie, other players, "wake on wireless" doesn't exist... and one more thing... but that's at the end.)

3.
The Touch might be serving other players, due to this it needs to be possible to turn it on remotely without standing beside the Touch. People that want to play music in their bedroom in the morning doesn't want to be forced to get up and walk into the living room and push a power button on the Touch to be able to start playing music on their Radio in the bedroom.

And how do you propose to do that if the Touch is wireless? Even if it is WOL, it will be 'on' and still drawing virtuallly the same power.

And the one I was saving: if it is off and you want the player in the bedroom to play your favorite playlist at 6:00am... how will it do that when it is off?

[erland]

That's not what the person I replied to asked for: he wanted -conpletely- off. Zero power.

That is plain and simple impossible without a physical switch.

I completely agree, if you want -completely off-, just get a power strip with a physical switch or similar solution.

The power difference between on and off on the touch is not significant: the difference is the display power.

Ok, I thought it was the hard drive of the attached USB that caused most power usage or the WiFi circuits if WiFi is used. If it's the display, we just need a off screen saver that turns off the display into low power mode. If I remember correctly there is a "Screen off" screen saver but I'm not sure if it decreases the power usage.

There is a menu option to do just that: turning it into some quasi off state and believing it is then ok to detach a USB drive would lead people to forget that the drive is still being read by some other player...

You would have to bring up a dialog box: "I am not turning off: the Kitchen player is still attached... "

I agree, it's not easy to get this user friendly both when used as single player (as most mass market users use it) and when used in a setup with multiple players (as many more advanced users use it). I just feel that sometimes we tend to make it more complicated for non technical users just to make it work really good for people on this forum who typically is more advanced users. I suspect that most users that use the built-in server in the Touch are only going to use it for a single player (the Touch itself). People with many players are probably also going to want the more advanced features which is available if you have a separate Squeezebox Server on a computer. There are exceptions to this rule, but I think most users with many players are going to be happier with a separate server.

For a non technical users with only a single player, I still feel that most would just want to turn off the device to be sure it's safe to disconnect the USB drive. Actually, most of them probably just expect to stop music and then be able to disconnect the USB drive, something that's not safe on a Windows formatted drive.

However, maybe I'm getting a bit off topic. Assuming the screen off screen saver decreases the power uses and the USB hard drive doesn't use a lot of power when it isn't used, that should be enough. For people that's not satisfied until the device is completely off, get a separate power switch because the Touch hardware will not get one. It's not possible to add one in software since there isn't any physical button that can be used to turn it on afterwards. The future will tell if future products will have an off switch but I suspect they won't, some low power standby mode will make most users happier.

[Siegfried Löffler]

> No. It has nothing at all to do with Linux.
>
> 1) If you turn off a device with a remote, and it is -really- off: how
> will you turn it back on? It's off: it has no IR sensor waiting for
>

By pressing a physical button. Not with a remote control. Honestly, I could
live with that. And I would prefer it.


> 2) A SB Touch can serve multiple players: if you turn 'off' the Touch
> in the living room, you won't be able to play music it was serving to
> the Radio in the Kitchen. It's off. It doesn't do anything when off.
> People would be very annoyed.
>

It could, but that very function is so buggy that it takes days to get it
working.
And it would be a lame excuse. One could still make that a choice that the
end user makes. I would even be willing to physically press the button in
the living room on the (few) days where I want the Touch to serve another SB
in the kitchen...

And yes, maybe you won't believe it, but I do physically switch of my TV
set. For the same reason. I rarely watch TV anyhow and I would be pissed off
with the device being responsible for pollution...

[snarlydwarf]

> No. It has nothing at all to do with Linux.
>
> 1) If you turn off a device with a remote, and it is -really- off: how
> will you turn it back on? It's off: it has no IR sensor waiting for
>

By pressing a physical button. Not with a remote control. Honestly, I could
live with that. And I would prefer it.

A power strip costs $5 and gives you a switch.

There you go, your problem is solved.

[aubuti]

I apologize for having been offensive. Here's a list of Average power per capita, though: http://en.wikipedia.org/wiki/List_of...ty_consumption

Hmm. First you say "Man, americans!", and then you post a link showing higher per capita electricity consumption in Iceland, Norway, Finland, Canada, Qatar, Sweden, Luxembourg, and Kuwait. I'm confused.

(Not really -- I know yanks consume too much energy. I just don't see why you dragged out evidence _against_ the point you were trying to make.)

[Siegfried Löffler]

On Tue, Aug 3, 2010 at 3:44 PM, snarlydwarf <
snarlydwarf.4f4fan1280843163 (AT) no...limdevices.com> wrote:

> A power strip costs $5 and gives you a switch.
>
> There you go, your problem is solved.
>
>
Yeah - but then you radically would switch off a Linux system without
properly shutting down the file systems etc. - it would only be a question
of time and you would end up with corrupted file systems. That's exactly
what I mean: No easy solution with Linux based architecture to shutdown
completely.

Don't get me wrong - I still like the Linux based architecture very much. I
just don't think that in terms of "green" it is the best solution mankind
will ever find...

[snarlydwarf]

Yeah - but then you radically would switch off a Linux system without
properly shutting down the file systems etc. - it would only be a question
of time and you would end up with corrupted file systems. That's exactly
what I mean: No easy solution with Linux based architecture to shutdown
completely.

Don't get me wrong - I still like the Linux based architecture very much. I
just don't think that in terms of "green" it is the best solution mankind
will ever find...

Linux has nothing to do with it.

Yanking power from ANY drive that is potentially being written to is bad.

What happens when you're mid-write and the drive loses power for any reason? Do you think the drive has some reserve power backup to ensure the write is completed before spinning down? What happens when the drive is only able to write half a sector before the power is gone?

This has nothing to do with the OS: it is the nature of mechanical media (especially, though an SSD would have a similar problem if power is removed at the wrong time -- it just has a smaller window since it is faster writing).

[Siegfried Löffler]

On Tue, Aug 3, 2010 at 10:49 PM, snarlydwarf <
snarlydwarf.4f4yxb1280868603 (AT) no...limdevices.com> wrote:

>
> Siegfried Löffler;566396 Wrote:
> Linux has nothing to do with it.
>
> Yanking power from ANY drive that is potentially being written to is
> bad.
>

That's true - but as in general I do know when I would write, I could live
with that.

Shutting down an ext2 fs without doing shutdown would not be good at all.

Yes you are in theory right and even for a VFAT filesystem you'd better shut
down - however, FAT file systems are less fragile, in the old DOS days there
was no shutdown... So yes, Linux HAS something to do with that. Or better:
Any multitasking OS ... Not that I would now say we should build a touch
version on MS-DOS... but still it's an unsolved issue. ( A potential
solution could be to mount all FS in Read Only and only have a /tmp in read
write that is reformatted at every boot.)

Anyhow: The point is, there is no good solution so far for powering the
stuff fully down. The power cord for 5$ certainly is not a good solution. So
I will probably just leave it switched on. And I can live with that if I can
manage to make the USB drive on the Touch work. However, getting it to work
is a nightmare with all these bugs in the scanner, memory limitations,
drives getting mounted read-only. I already spent several evenings, and for
the time being the only working solution I have is to have my PC running as
server. And that's really really frustrating.--
Siegfried Löffler * http://dg1sek.home.pages.de * Tel1 +33 95173 4711 *
Tel2: +49 7145 969098 * Fax +33 95673 4711