<div dir="ltr"><div>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 😬 )<br></div><div><br></div><div>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<br></div><div><br></div><div>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?)</div><div><br></div><div>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.</div><div><br></div><div>Is this maybe why Andrew is not able to hibernate?<br></div><div><br></div><div>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 🤔<br></div><div><br></div><div>Regards</div><div>Geetam</div><div><br></div><div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div></div><div>-- <br></div><div>I don't know<br>...<br></div><div>I don't know what it is<br>...<br></div><div>I don't know what it is that I don't know<br><br></div><div>Isn't it beautiful<br></div></div></div></div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, 16 Sept 2022 at 08:04, Colin Shorts <<a href="mailto:colin.shorts@gmail.com">colin.shorts@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="auto"><div>Hi Andrew, I'd be inclined to add a smidgen more swap to be on the safe side.</div><div dir="auto"><br></div><div dir="auto">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?</div><div dir="auto"><br></div><div dir="auto">I'm in the middle of redecorating my home office or I'd give it a bash myself 😃</div><div dir="auto"><br></div><div dir="auto">Cheers,</div><div dir="auto">Colin</div><div dir="auto"><br><div class="gmail_quote" dir="auto"><div dir="ltr" class="gmail_attr">On Fri, 16 Sept 2022, 01:16 Andrew Smith, <<a href="mailto:asmith9983@gmail.com" target="_blank">asmith9983@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hi Colin<div>I have 32Gb of swap, with <i>htop</i> reporting none used in normal operation.</div><div>Suspend works OK. Given the minimal energy consumed overnight on suspend, I may just continue using that until I can investigate further how <i>suspend-then-hibernate</i> is meant to operate by reading the sourcecode of <i>systemctl. </i></div><div><div><div dir="ltr"><div dir="ltr">Andrew</div></div></div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, 14 Sept 2022 at 20:07, Colin Shorts <<a href="mailto:colin.shorts@gmail.com" rel="noreferrer" target="_blank">colin.shorts@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="auto">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.<div dir="auto"><br></div><div dir="auto">-Colin</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, 14 Sept 2022, 18:03 Andrew Smith, <<a href="mailto:asmith9983@gmail.com" rel="noreferrer" target="_blank">asmith9983@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Guys<div>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</div><div>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.</div><div>I've tried "systemctl suspend-then-hibernate" from root CLI, but I get essentially a fresh boot. </div><div><br></div><div>Any suggestions ?</div><div>I'm running kernel 5.4.0-125-generic from Ubuntu, in 32Gb RAM, and typically have a around hundred tabs open on Chrome.<br></div><div><div><div dir="ltr"><div dir="ltr">Andrew</div></div></div></div></div>
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