[EdLUG] Linux hibernate
Roy
roy at crossford.net
Sat Sep 17 17:47:51 UTC 2022
Isn't the hibernate image compressed these days?
That means that it might fit with some swap in use. It might not too.
Regards,
Roy Bamford
On 17/09/2022 16:50, Geetam wrote:
> I only know the theory of hibernating, so please fill in a bit of
> hibernating knowledge that I do not have. (I am so old-fashioned that
> I shut down and boot up 😬 )
>
> When hibernating, the state of internal memory is stored on disk.
> Linux uses the swap partition on disk for this. So your swap partition
> needs to be large enough, i.e. at least as large as your internal
> memory - in your case 32Gb
>
> BUT WHAT HAPPENS when you have so much open on your desktop that your
> internal memory wasn't big enough and some of the less active
> processes have been swapped to swap space? (I am sure most of us avoid
> that, but that is what swap space is for, isn't it?)
>
> Say you have 40GB in use (32Gb in internal memory, 8Gb swapped to swap
> space). Is hibernating going to try to save 40GB into swap space? That
> won't fit into the 32Gb swap partition... Or is it only writing the
> 32Gb in internal memory to the swap partition clobbering the 8Gb that
> was there? Then the full state of your desktop cannot be restored.
>
> Is this maybe why Andrew is not able to hibernate?
>
> I am sure someone in the Linux world has thought about this, but I
> think we have forgotten because we try to have so much internal memory
> that swaps space is not used and the issue hardly ever arises these
> days. Still, I am curious 🤔
>
> Regards
> Geetam
>
> --
> I don't know
> ...
> I don't know what it is
> ...
> I don't know what it is that I don't know
>
> Isn't it beautiful
>
>
> On Fri, 16 Sept 2022 at 08:04, Colin Shorts <colin.shorts at gmail.com>
> wrote:
>
> Hi Andrew, I'd be inclined to add a smidgen more swap to be on the
> safe side.
>
> I take it `sudo pm-hibernate` doesn't work (correctly) either? Are
> the kernel parameters getting set at boot (I think dmesg should
> say which device will be used)? Is your swap partition on lvm, are
> you mounting it using the uuid?
>
> I'm in the middle of redecorating my home office or I'd give it a
> bash myself 😃
>
> Cheers,
> Colin
>
> On Fri, 16 Sept 2022, 01:16 Andrew Smith, <asmith9983 at gmail.com>
> wrote:
>
> Hi Colin
> I have 32Gb of swap, with /htop/ reporting none used in normal
> operation.
> Suspend works OK. Given the minimal energy consumed overnight
> on suspend, I may just continue using that until I can
> investigate further how /suspend-then-hibernate/ is meant to
> operate by reading the sourcecode of /systemctl. /
> Andrew
>
>
> On Wed, 14 Sept 2022 at 20:07, Colin Shorts
> <colin.shorts at gmail.com> wrote:
>
> I'm no expert on hibernate (I use suspend myself), but
> iirc you'll need at least as much free swap as system ram
> +used swap. 64GB doesn't sound unreasonable as a starting
> point assuming you've got enough space and considering how
> much Chrome can chew up.
>
> -Colin
>
> On Wed, 14 Sept 2022, 18:03 Andrew Smith,
> <asmith9983 at gmail.com> wrote:
>
> Guys
> For quite a while, I've been putting my system into
> suspend mode, which was successful , apart from an
> odd occassion. I now want to try saving more energy
> I've tried powering down, but would like it to restart
> in the same state rather than with a new login, as I
> had with suspend.
> I've tried "systemctl suspend-then-hibernate" from
> root CLI, but I get essentially a fresh boot.
>
> Any suggestions ?
> I'm running kernel 5.4.0-125-generic from Ubuntu, in
> 32Gb RAM, and typically have a around hundred tabs
> open on Chrome.
> Andrew
> --
> EdLUG mailing list
> EdLUG at mailman.lug.org.uk
> https://lists.edlug.org.uk/mailman/listinfo/edlug
>
> --
> EdLUG mailing list
> EdLUG at mailman.lug.org.uk
> https://lists.edlug.org.uk/mailman/listinfo/edlug
>
> --
> EdLUG mailing list
> EdLUG at mailman.lug.org.uk
> https://lists.edlug.org.uk/mailman/listinfo/edlug
>
> --
> EdLUG mailing list
> EdLUG at mailman.lug.org.uk
> https://lists.edlug.org.uk/mailman/listinfo/edlug
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.edlug.org.uk/pipermail/edlug/attachments/20220917/8e83cd90/attachment.htm>
More information about the EdLUG
mailing list