I've been using Ubuntu for about 8 months now, and the time it takes to un-hibernate seems to vary by minutes sometimes. I haven't been able to see a correlation between what's open when it's hibernated and how long it takes. I'm wondering how to go about diagnosing this?
I spun off the question about timing the wakeup to a separate question.
The official hibernate troubleshooting page is Debugging Kernel Hibernate
However, this forums article looks like it might be more useful (start at comment #4).
I think the time taken to (un)hibernate will depend mainly on the RAM and swap usage. When you hibernate, the data in RAM is basically saved into swap and when you unhibernate it is loaded from disk. This will be slower when there is more RAM to move. When some swap is used it will most likely take even longer.
It may help with speed if you close the programs which you don't need to sustain their current state before hibernating. I always shut down completely if possible.
I don't think there is an internal way to time (un)hibernation.
Not only open applications, but also devices plugged in can affect hibernate time as they often have to be shut down and then brought up in just the right order and have timeouts and such applied to them. Maybe it takes longer when you've got a USB hub or printer plugged in? or when you've been using the audio device a lot?
Yes I've noticed this myself. I'm using Linux Mint 19.1, and hibernation takes some about 5 minutes but some other times it will be quick even that nothing changed! Wake up from hibernation is fast enough but the issue is the computer will remain slow for about 5 minutes or more with constant disk access which I fail to know which service is causing. I feel the whole hibernation speed depends on the following:
Anyways I feel that hibernation/standby processes needs a lot of improvement in Linux, Windows is vastly superior in this area.
