New on LowEndTalk? Please Register and read our Community Rules.
All new Registrations are manually reviewed and approved, so a short delay after registration may occur before your account becomes active.
All new Registrations are manually reviewed and approved, so a short delay after registration may occur before your account becomes active.
Xen CPU Core Sharing
Hi,
I want to start providing Xen VPS.
RAM and Disk will NOT be oversold. Obviously it will be a premium managed service so I need to ensure customers are happy!
However, I see most dedicated servers that I want to fit in price range, are Xeon Quad Core, for example, Intel Xeon E3-1245v2, and this means I could only fit 4 VPS per host node if I dedicate them a full core. Obviously this is not profitable unless you own your own full rack or own datacenter, which is definitely going to be the case down the road but not possible at this point.
I want to check, is there any way I can create three 4-Core VPS on a single Quad Core server, with Xen? Other resources like RAM and Disk Space will NOT be oversold.
Thanks for your input,
Shovenose
Comments
Sure you can, xen has different credit schedulers. Provide them the ability to burst to all 4 cores but set minimum limits in case all are busy. Linode seems to be admitting this now with their plans, where you get "4 cpu / xx priority" for example.
That said, for a premium managed service you should really be building boxes with 2x E5-2660 or better.
If you tell a monthly VPS prices for the service you gonna offer will be great ...
Well, it has hyperthreading, so xen will see 8 CPUs.
You can give weighted priority, depending on your customers, if you have fully managed services you will know each one in detail and their needs.
The problem today is not with CPU, but with storage. Most of our nodes are way below 30% CPU usage because we dont have IO wait states as the storage is really fast (while we offer small space, it is of very good quality) so the CPU does real work, not sits there waiting for data.
If you get a good storage and you take care so you dont have abuse (being fully managed will be easy), the CPU will be enough for most things, even with many VPSes.
thanks that makes sense. Iowait sucks!!
So with xen I can place 2-3 cores per core no problem?
I am not sure that makes sense.
You can have 8 logical cores (an e3 with hyperthreading and 4 physical cores) and put up 10 virtual machines with 8 cores. They will use them as they need and in case of conflict (need more than the CPU can do) will have priority thrown at them as you put the weight on each machine, so, normally they will have equal share (fair share), but if not, you give more priority to one machine and less to another, so the virtual cores in each will be doing more or less depending on that.
If you plan well, there will never be a conflict, i you have someone doing SETI at home, tho, you will have to either kick them, or nice the process so when the others need the share, it will not matter. Not that it is really possible without asking the customer, in a regular server, but here, you can simply give him the least priority so he will use only leftovers, nevertheless, a nice offer and approach can work miracles at times.
You may never know, the worst abuser might be the nicest guy you will ever meet