0
I'm suffering from heavy performance issues more detailed explained in this and that other question. From what I've tested so far, there's a direct relationship to the amount of memory assigned to a VM: Problem occurs with 48 GiB of RAM and doesn't with only 6 GiB or even 24 GiB of RAM. Additionally, it seems that enabling the setting largepages
of the VM has a positive impact as well, even though it couldn't work around the problem entirely. It only seems to happen a bit later.
That is interesting, because that setting doesn't seem to be enabled by default on Linux, the docs only tell about ~5 % improvement, not that it's necessary at all for decent performance at some RAM size, and additionally there are circumstances in which largepages
is ignored by VirtualBox altogether.
00:00:42.866663 PGMR3PhysAllocateLargePage: allocating large pages takes too long (last attempt 103 ms; nr of timeouts 11); DISABLE
https://www.virtualbox.org/attachment/ticket/16518/VBox_16518_5112.log#L1154
So currently in my opinion it seems unclear under which circumstances largepages
is not only suggested, but required by VirtualBox to operate properly. To distinguish that, one needs to know which RAM sizes for VMs were used in the past without largepages
and which weren't because of performance issues like those I'm seeing, if at all.
@tiago-caldeira Your new title targets only people who think to know the exact answer and I very much doubt that many are out there. I want a broad audience, lots of experiences and create the correct answer afterwards. If such exists at all. – Thorsten Schöning – 2018-05-28T13:22:51.537
We're not a discussion forum. This is an Q&A website. We want technical insights and not "i got 40gb max" and then other user answers "i already tried with 42gb and it works". And that title was really asking for that. The new title will certainly unleash accurate answers. – CaldeiraG – 2018-05-28T15:23:48.890
If no one knows the exact answer, because it is not documented or such anywhere, experiences from people saying what worked and what didn't is the only way to create the needed facts! I already spent DAYS looking for the answer and didn't find anything anywhere. But go ahead, tell me with your two months membership what this site is all about... – Thorsten Schöning – 2018-05-28T16:08:23.333
Alright, I get it. But the newer title is more appropriate here. Other users accepted my suggested edit. You don't want to mess around with me because I only joined 2 months ago, if I wasn't a great user of Superuser, I wouldn't get 1k+ reputation ;)
– CaldeiraG – 2018-05-29T11:20:58.377