Hi all! I'm a linode customer but I had to buy from another company for a client this week. Nothing spectacular (they've got nothing on you guys) but there's one odd thing.
If I run htop from my NJ Linode, I see 4 CPUs. Magic. If I run htop on my new UK Tagadab VPS, I see one. I used to have another VPS with another random company and I saw 8 CPUs.
I might be looking at this like a typical middle-manager ("bigger number is better, right?") but surely having access to more than one processor at a time is going to help apps that multi-thread (database mainly), no?
So I sent them an email telling them all this and their chap sent this back today:
Quote:
Hi Oli,
> Hi there. I just bought a VPS package and I notice that I only have
> access to one CPU thread.
>
> I've dealt with several other XEN hosting services and have always had
> access to at least 4 cores, sometimes 8.
This means that they are probly not ring-fencing the CPU resources very
carfully.
The VPS host has 8 cores in total, and 16G of RAM. Your 512M VPS should
therefore have 1/32nd of the total CPU resources if all VMs on the host
are running high-cpu tasks. In fact you get 1/32nd ring-fenced for your
VM but you can use up to 1/8th (one full core) if other VMs are not
using it. (The actual average CPS usage on our hosts is normally less
than 5%).
This is important because since our VMs allow full root access we
frequently see 'spinning' processes - software written by or installed
by customers which hits an infinite loop and just munches CPU forever.
If we allowed burst CPU across all 8 cores you might find your VM
fighting for CPU resources more often than it currently does.
If you need more CPU resources than a single core can offer then I
suggest moving to a dedicated server where of course you can have as
many cores as you need.
Now I don't know the guts of how XEN splits resources down. No idea at all. That's why I'm a customer... But if I'm theoretically getting unsecure access here or shoddy performance there, I'd like to know.
If a Linoder knows their setup is secure and you think that a 1-core limit would harm my performance, could you give me something I could reply with?
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