2007-05-26 23:51:44

by Bill Davidsen

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Subject: Documentation on /sys/power/resume

Not in the ABI doc, is there and doc at all, and if not could someone
who knows where it's used might give me a hint, as a quick look didn't
bring enlightenment. Or is it a future hook which doesn't work yet?

--
Bill Davidsen <[email protected]>
"We have more to fear from the bungling of the incompetent than from
the machinations of the wicked." - from Slashdot


2007-05-27 10:47:54

by Rafael J. Wysocki

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Subject: Re: Documentation on /sys/power/resume

Hi,

On Sunday, 27 May 2007 01:51, Bill Davidsen wrote:
> Not in the ABI doc, is there and doc at all, and if not could someone
> who knows where it's used might give me a hint, as a quick look didn't
> bring enlightenment. Or is it a future hook which doesn't work yet?

That's something that in theory may allow you to resume the system from
and initrd script.

Basically, you write your resume device's major and minor numbers
into it as the "MAJ:MIN" string (eg. "8:3" for /dev/sda3 on my box) and the
kernel will try to read the image from this device and restore it.

It only works with partitions and the use of it us discouraged, so it's
deliberately undocumented.

Greetings,
Rafael


--
If you don't have the time to read,
you don't have the time or the tools to write.
- Stephen King

2007-05-27 12:51:17

by Bill Davidsen

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Subject: Re: Documentation on /sys/power/resume

Rafael J. Wysocki wrote:
> Hi,
>
> On Sunday, 27 May 2007 01:51, Bill Davidsen wrote:
>> Not in the ABI doc, is there and doc at all, and if not could someone
>> who knows where it's used might give me a hint, as a quick look didn't
>> bring enlightenment. Or is it a future hook which doesn't work yet?
>
> That's something that in theory may allow you to resume the system from
> and initrd script.
>
> Basically, you write your resume device's major and minor numbers
> into it as the "MAJ:MIN" string (eg. "8:3" for /dev/sda3 on my box) and the
> kernel will try to read the image from this device and restore it.
>
> It only works with partitions and the use of it us discouraged, so it's
> deliberately undocumented.
>
Thanks, that's just different enough from what little info I had to make
what I have not work. I'm looking at resume from a non-swap location.

--
Bill Davidsen <[email protected]>
"We have more to fear from the bungling of the incompetent than from
the machinations of the wicked." - from Slashdot

2007-05-27 13:01:35

by Rafael J. Wysocki

[permalink] [raw]
Subject: Re: Documentation on /sys/power/resume

On Sunday, 27 May 2007 14:53, Bill Davidsen wrote:
> Rafael J. Wysocki wrote:
> > Hi,
> >
> > On Sunday, 27 May 2007 01:51, Bill Davidsen wrote:
> >> Not in the ABI doc, is there and doc at all, and if not could someone
> >> who knows where it's used might give me a hint, as a quick look didn't
> >> bring enlightenment. Or is it a future hook which doesn't work yet?
> >
> > That's something that in theory may allow you to resume the system from
> > and initrd script.
> >
> > Basically, you write your resume device's major and minor numbers
> > into it as the "MAJ:MIN" string (eg. "8:3" for /dev/sda3 on my box) and the
> > kernel will try to read the image from this device and restore it.
> >
> > It only works with partitions and the use of it us discouraged, so it's
> > deliberately undocumented.
> >
> Thanks, that's just different enough from what little info I had to make
> what I have not work. I'm looking at resume from a non-swap location.

Only suspend2 can do this right now. The built-in swsusp can resume from a
swap file as long as it's not located on LVM.

Greetings,
Rafael

2007-05-27 13:14:50

by Bill Davidsen

[permalink] [raw]
Subject: Re: Documentation on /sys/power/resume

Rafael J. Wysocki wrote:
> On Sunday, 27 May 2007 14:53, Bill Davidsen wrote:
>
>> Rafael J. Wysocki wrote:
>>
>>> Hi,
>>>
>>> On Sunday, 27 May 2007 01:51, Bill Davidsen wrote:
>>>
>>>> Not in the ABI doc, is there and doc at all, and if not could someone
>>>> who knows where it's used might give me a hint, as a quick look didn't
>>>> bring enlightenment. Or is it a future hook which doesn't work yet?
>>>>
>>> That's something that in theory may allow you to resume the system from
>>> and initrd script.
>>>
>>> Basically, you write your resume device's major and minor numbers
>>> into it as the "MAJ:MIN" string (eg. "8:3" for /dev/sda3 on my box) and the
>>> kernel will try to read the image from this device and restore it.
>>>
>>> It only works with partitions and the use of it us discouraged, so it's
>>> deliberately undocumented.
>>>
>>>
>> Thanks, that's just different enough from what little info I had to make
>> what I have not work. I'm looking at resume from a non-swap location.
>>
>
> Only suspend2 can do this right now. The built-in swsusp can resume from a
> swap file as long as it's not located on LVM.
>
Sounds like sispend2 is still needed, I haven't needed a suspending
kernel in a few years, and I was hoping that with suspend working in
mainline that resume would have been implemented. Sounds as if that's
not the case, my swap is RAID1, I was hoping to resume from one of the
mirrors, since they are based on a partition. No joy wit or without
/sys/power/resume, so I'll look further.

--
bill davidsen <[email protected]>
CTO TMR Associates, Inc
Doing interesting things with small computers since 1979

2007-05-27 15:36:19

by Matthew Garrett

[permalink] [raw]
Subject: Re: Documentation on /sys/power/resume

On Sun, May 27, 2007 at 09:17:25AM -0400, Bill Davidsen wrote:

> Sounds like sispend2 is still needed, I haven't needed a suspending
> kernel in a few years, and I was hoping that with suspend working in
> mainline that resume would have been implemented. Sounds as if that's
> not the case, my swap is RAID1, I was hoping to resume from one of the
> mirrors, since they are based on a partition. No joy wit or without
> /sys/power/resume, so I'll look further.

Should work absolutely fine as long as you set up the RAID before
attempting to resume.

--
Matthew Garrett | [email protected]