<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style></style></head><body lang=NL-BE link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Regarding fine tuning my explanation about what system does de actual mounting of Hugepages, you’re probably right…. Thanks for the correction.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>On upstart systems (like Ubuntu) the mounting of Hugepages is done by the init script qemu-kvm.conf<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span lang=NL style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>Van:</span></b><span lang=NL style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> G. Richard Bellamy [mailto:rbellamy@pteradigm.com] <br><b>Verzonden:</b> zondag 1 februari 2015 0:02<br><b>Aan:</b> Dominique Ramaekers<br><b>CC:</b> libvirt-users@redhat.com<br><b>Onderwerp:</b> Re: [libvirt-users] HugePages - can't start guest that requires them<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal><span style='font-family:"Verdana","sans-serif"'>Yeah, Dominique, your wiki was one of the many docs I read through before/during/after starting down this primrose path... thanks for writing it. I'm an Arch user, and I couldn't find anything to indicate qemu, as its compiled for Arch, will look in /etc/default/qemu-kvm. And now that I've got the right page size, the instances are starting...<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Verdana","sans-serif"'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Verdana","sans-serif"'>The reason I want to use the page element to the hugepages directive is that I want to target a numa node directly - in other words, I like the idea of one VM running on Node 0, and the other running on Node 2.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Verdana","sans-serif"'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Verdana","sans-serif"'>Your comment about libvirt taking care of the hugepages mount isn't consistent with my reading or experience - on a systemd-based system, systemd takes care of the hugetlbfs mount to /dev/hugepages, and the libvirt builds the /dev/hugepages/qemu... directory structure. At least that's what I've seen.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Verdana","sans-serif"'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Verdana","sans-serif"'>-rb<o:p></o:p></span></p></div></div><div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>On Sat, Jan 31, 2015 at 11:43 AM, Dominique Ramaekers <<a href="mailto:dominique.ramaekers@cometal.be" target="_blank">dominique.ramaekers@cometal.be</a>> wrote:<o:p></o:p></p><p class=MsoNormal>Did you create a mount for the hugepages? If you did, that's maybe the problem. I did that also at first but with libvirt it isn't necessary and in my case, it broke hugepages...<br><br>If I'm not mistaking, libvirt takes care of the hugepages mount.<br><br>A while ago, I've written a wiki to use hugepages in libvirt and Ubuntu. <a href="https://help.ubuntu.com/community/KVM%20-%20Using%20Hugepages" target="_blank">https://help.ubuntu.com/community/KVM%20-%20Using%20Hugepages</a><br><br>Maybe this helps?<br><br>________________________________________<br>Van: G. Richard Bellamy [<a href="mailto:rbellamy@pteradigm.com">rbellamy@pteradigm.com</a>]<br>Verzonden: zaterdag 31 januari 2015 0:33<br>Aan: <a href="mailto:libvirt-users@redhat.com">libvirt-users@redhat.com</a><br>Onderwerp: [libvirt-users] HugePages - can't start guest that requires them<o:p></o:p></p><div><div><p class=MsoNormal style='margin-bottom:12.0pt'><br>Hello All,<br><br>I'm trying to enable hugepages, I've turned off THP (Transparent Huge<br>Pages), and enabled hugepages in memoryBacking, and set my 2MB<br>hugepages count via sysctl.<br><br>I'm getting "libvirtd[5788]: Failed to autostart VM 'atlas': internal<br>error: Unable to find any usable hugetlbfs mount for 16777216 KiB"<br>where atlas is one of my guests and 16777216 KiB is the amount of<br>memory I'm trying to give to the guest.<br><br>Yes, i can see the hugepages via numastat -m and hugetlbfs is mounted<br>via /dev/hugepages and there is a dir structure<br>/dev/hugepages/libvirt/qemu (it's empty).<br><br>HugePages is big enough to accommodate the 16G i'm allocating... and<br>changing the perms on that directory structure to 777 doesn't work<br>either.<br><br>Any help is much appreciated.<br><br>HOST: <a href="http://sprunge.us/SEdc" target="_blank">http://sprunge.us/SEdc</a><br>GUEST: <a href="http://sprunge.us/VCYB" target="_blank">http://sprunge.us/VCYB</a><br><br>Regards,<br>Richard<o:p></o:p></p></div></div><div><div><p class=MsoNormal>_______________________________________________<br>libvirt-users mailing list<br><a href="mailto:libvirt-users@redhat.com">libvirt-users@redhat.com</a><br><a href="https://www.redhat.com/mailman/listinfo/libvirt-users" target="_blank">https://www.redhat.com/mailman/listinfo/libvirt-users</a><o:p></o:p></p></div></div></div><p class=MsoNormal><o:p> </o:p></p></div></div></body></html>