Your case is valid and I use it also. Using 2 cores as 8 virtual cores for _one_ machine is not the same thing.
On Mon, Dec 23, 2013 at 11:03 PM, Joshua Harlow <harlo...@yahoo-inc.com> wrote: > It depends on the use-case, there is a point when most of the time the VMs > on the compute node are idle. > > A use-case yahoo! is doing is letting developers have many VMs, in this > case those VMs are mostly idle. > > Given a hypervisor with 12 cores, we can place say 12x2 core VMs on there, > this is a total of 24 VM cores, in reality most of the time *all* the > developers using those VMs will not be utilizing all 24 'virtual' cores > (highly unlikely that all those users conspired to do this at the same > time, even if they do this is where the linux scheduler will get > involved). So there are reasons to do this (save money, improve > efficiency), of course figuring out the right balance is up to u. Likely > don't do 8 vms cores on a 2 core box, I would recommend buying better > hardware before u do this ;) > > On 12/23/13, 12:55 PM, "Cristian Falcas" <cristi.fal...@gmail.com> wrote: > >>There is no point in using 8 virtual cores in compute node with 2 >>cores. The same is valid for using swap as memory to reach the desired >>12gb. >> >>Of course, if you don't plan on using that machine for any real work, >>you can do it. >> >> >> >>On Mon, Dec 23, 2013 at 6:39 PM, Joshua Harlow <harlo...@yahoo-inc.com> >>wrote: >>> Nope, u can over provision on most all of the resources (CPU, ram, >>>disk) u >>> described there. Ram is the tricky one as the Linux oom killer may >>>start to >>> get involved when u push the ram limits to high. But there is nothing >>> stopping u from running 8 or more vms on a box, depending on the over >>> provision ratio u are ok with... >>> >>> Sent from my really tiny device... >>> >>> On Dec 23, 2013, at 3:55 AM, "Vikas Parashar" <para.vi...@gmail.com> >>>wrote: >>> >>> Thanks Cristian, >>> >>> Will elasticity be limited to 4 Cores/4GB (The max capacity of a >>>physical >>> host) ? >>> >>> >>> On Mon, Dec 23, 2013 at 5:00 PM, Cristian Falcas >>><cristi.fal...@gmail.com> >>> wrote: >>>> >>>> Hi, >>>> >>>> From what I know you can resize a machine, but this involves >>>> rebuilding the instance: openstack will create a snapshot of the >>>> machine an recreate the instance with the new snapshot and a new >>>> flavor. This is not very fast from my experience, so you will have a >>>> considerable downtime doing this, depending on the size of the current >>>> instance and how fast is your storage. >>>> >>>> Best regards, >>>> Cristian Falcas >>>> >>>> >>>> >>>> On Mon, Dec 23, 2013 at 12:03 PM, Vikas Parashar <para.vi...@gmail.com> >>>> wrote: >>>> > Hi, >>>> > >>>> > IaaS is all about elastic computing. I can stretch resources as per >>>>my >>>> > need >>>> > - increasing/decreasing the number of cores, RAM allocated etc.. >>>> > >>>> > My question is - how does openStack achieve this elasticity for both >>>> > computation and RAM. >>>> > >>>> > If I create an image with 2 cores and 4 GB RAM (and one day I need to >>>> > increase this to, lets say - 6 Cores and 12 GB RAM), but all the >>>> > physical >>>> > hosts that I currently have (for Compute and RAM) at my disposal >>>>have a >>>> > max >>>> > of 4 Cores and 4 GB RAM each.. >>>> > >>>> > Using openStack - >>>> > >>>> > a) is this possible (as long as the total cores and total RAM >>>>required >>>> > is >>>> > less than the group-total) ? If yes, how is this achieved. >>>> > >>>> > b) or the elasticity will be limited to 4 Cores/4GB (The max >>>>capacity >>>> > of a >>>> > physical host) ? If no, then is it possible to achieve it ? >>>> > >>>> > _______________________________________________ >>>> > Mailing list: >>>> > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack >>>> > Post to : openstack@lists.openstack.org >>>> > Unsubscribe : >>>> > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack >>>> > >>> >>> >>> _______________________________________________ >>> Mailing list: >>>http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack >>> Post to : openstack@lists.openstack.org >>> Unsubscribe : >>>http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack > _______________________________________________ Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack Post to : openstack@lists.openstack.org Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack