resume from swap partition under LVM

resume from swap partition under LVM

[Uwe Geuder]

Hi!

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/power/swsusp.txt?id=refs/tags/v4.1#n411 
reads:

> Q: Can I suspend-to-disk using a swap partition under LVM?
> 
> A: No. You can suspend successfully, but you'll not be able to
> resume. uswsusp should be able to work with LVM. See suspend.sf.net.

Is that information still up to date? 

It works for me most times, just occasional crashes during resume. 

Regards,

Uwe Geuder
--
Nomovok Ltd.
Tampere, Finland
uwe.gxuder@nomovok.com (bot test: humans correct 1 obvious spelling error)

Re: resume from swap partition under LVM

[Uwe Geuder]

On 28 June 2015 at 00:59, Uwe Geuder
<linuxkernel2015-ugeuder@snkmail.com> wrote: 

> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/power/swsusp.txt?id=refs/tags/v4.1#n411
> reads:
>
>> Q: Can I suspend-to-disk using a swap partition under LVM?
>>
>> A: No. You can suspend successfully, but you'll not be able to
>> resume. uswsusp should be able to work with LVM. See suspend.sf.net.
>
> Is that information still up to date?

I guess I can reply myself. The "No" answer probably refers to the
kernel resuming itself just with the help of the command line
parameters. Of course that is not possible. I did not even think about
that possibility, because I have used LUKS encrypted disks longer than
hibernate/resume...

What I meant is 

echo -n "$major:$minor" > /sys/power/resume

I guess that should work just fine with LVM, shouldn't it.

I'll send a patch to clarify the answer in the FAQ.

Regards,

Uwe Geuder
-- 
Nomovok Ltd.
Tampere, Finland
uwe.gxuder@nomovok.com (bot test: humans correct 1 obvious spelling error)

[PATCH] PM / hibernate/resume: clarify documentation

[Uwe Geuder]

it was not the whole truth that kernel mode cannot be used with swap on LVM

Signed-off-by: Uwe Geuder <linuxkernel2015-ugeuder@snkmail.com>
---
 Documentation/power/swsusp.txt | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
index f732a83..8cc17ca 100644
--- a/Documentation/power/swsusp.txt
+++ b/Documentation/power/swsusp.txt
@@ -410,8 +410,17 @@ Documentation/usb/persist.txt.
 
 Q: Can I suspend-to-disk using a swap partition under LVM?
 
-A: No. You can suspend successfully, but you'll not be able to
-resume. uswsusp should be able to work with LVM. See suspend.sf.net.
+A: Yes and No.  You can suspend successfully, but the kernel will not be able
+to resume on its own.  You need an initramfs that can recognize the resume
+situation, activate the logical volume containing the swap volume (but not
+touch any filesystems!), and eventually call
+
+echo -n "$major:$minor" > /sys/power/resume
+
+where $major and $minor are the respective major and minor device numbers of
+the swap volume.
+
+uswsusp works with LVM, too.  See http://suspend.sourceforge.net/
 
 Q: I upgraded the kernel from 2.6.15 to 2.6.16. Both kernels were
 compiled with the similar configuration files. Anyway I found that
-- 
1.8.4.5

Re: [PATCH] PM / hibernate/resume: clarify documentation

[Pavel Machek]

On Mon 2015-06-29 23:35:05, Uwe Geuder wrote:
> it was not the whole truth that kernel mode cannot be used with swap on LVM
> 
> Signed-off-by: Uwe Geuder <linuxkernel2015-ugeuder@snkmail.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

Thanks for clarifying this.

(Hmm, and I guess we shoudl rename swsusp.txt -> hibernation.txt one
day :-).

									Pavel
> ---
>  Documentation/power/swsusp.txt | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
> index f732a83..8cc17ca 100644
> --- a/Documentation/power/swsusp.txt
> +++ b/Documentation/power/swsusp.txt
> @@ -410,8 +410,17 @@ Documentation/usb/persist.txt.
>  
>  Q: Can I suspend-to-disk using a swap partition under LVM?
>  
> -A: No. You can suspend successfully, but you'll not be able to
> -resume. uswsusp should be able to work with LVM. See suspend.sf.net.
> +A: Yes and No.  You can suspend successfully, but the kernel will not be able
> +to resume on its own.  You need an initramfs that can recognize the resume
> +situation, activate the logical volume containing the swap volume (but not
> +touch any filesystems!), and eventually call
> +
> +echo -n "$major:$minor" > /sys/power/resume
> +
> +where $major and $minor are the respective major and minor device numbers of
> +the swap volume.
> +
> +uswsusp works with LVM, too.  See http://suspend.sourceforge.net/
>  
>  Q: I upgraded the kernel from 2.6.15 to 2.6.16. Both kernels were
>  compiled with the similar configuration files. Anyway I found that

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