<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div><span></span></div><div><meta http-equiv="content-type" content="text/html; charset=utf-8"><div><blockquote type="cite"><div dir="ltr"><font color="#000000"><span style="background-color: rgba(255, 255, 255, 0);">Are there any documents going more deeply in these sort of considerations?</span></font></div></blockquote><div id="AppleMailSignature"><br></div>This is exactly what I have been searching for lately, too. Please let me know if you find anything (or blog posts, forums, books, etc). Thank you!<br><br>Sent from my mobile phone</div><div><br>On 6 Sep 2017, at 12:47, Gianluca Cecchi <<a href="mailto:gianluca.cecchi@gmail.com">gianluca.cecchi@gmail.com</a>> wrote:<br><br></div><blockquote type="cite"><div><div dir="ltr">Hello,<div>I was talking with a guy expert in VMware and discussing performance of VMs in respect of virtual cpus assigned to them in relation with mapping with the real hw of the hypervisor underneath.</div><div><br></div><div>One of the topics was numa usage and its overheads in case of a "too" big VM, in terms of both number of vcpus and memory amount.</div><div>Eg: </div><div>suppose host has 2 intel based sockets, with 6 cores and HT enabled and has 96Gb of ram (distributed 48+48 between the 2 processors)</div><div>suppose I configure a VM with 16 vcpus (2:4:2): would be the mapping respected at physical level or only a sort of "hint" for the hypervisor?</div><div>Can I say that it would perform better if I configure it 12 vcpus and mapping 1:6:2, because it can stay all inside one cpu?</div><div><br></div><div>And what if I define a VM with 52Gb of ram? Can I say that it would perform in general better if I try to get it all in one cpu related memory slots (eg not more than 48Gb in my example)?</div><div><br></div><div>Are there any documents going more deeply in these sort of considerations?</div><div><br></div><div>Also, if one goes and sizes so that the biggest VM is able to all-stay inside one cpu-memory, does it make sense to say that it will perform better in this scenario a cluster composed by 4 nodes, each one with 1 socket and 48Gb of memory instead of a cluster of 2 nodes, each one with 2 sockets and 96Gb of ram?</div><div><br></div><div>Hope I have clarified my questions/doubts.</div><div><br></div><div><br></div><div>Thanks in advance for any insight,</div><div>Gianluca </div></div>
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