Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Sign In with OpenID
Advertise on LowEndTalk.com

In this Discussion

Which one is the best performance? OpenVZ, XEN or KVM?

Which one is the best performance? OpenVZ, XEN or KVM?

yumiVPSyumiVPS Member
edited November 2011 in General

NO over sell

Tagged:

Comments

  • If you're looking for a platform with a less chance of overselling, that'd be Xen. But the providers are still able to oversell on hard disk and RAM.

    LoomHosts VPS Servers - Dallas VPS | Reliable, Affordable, Solid
  • Xen. We have tested with KVM, but are not getting anywhere near the results we get with Xen. It is improving fast so we are keeping an eye on the developments.

    I would not consider openvz, although most of the problems are created by overselling.

  • If not overselling, OpenVZ should provide the best performance since there is almost no virtualization overhead compated to bare metal server.

    Thanked by 2japon Ash_Hawkridge
  • Overselling is good. Excessive overselling is not. It's quite stupid to charge a lot more and leave unused resources on the node. Overselling can help keeping prices low while providing a great performance.

    maybe for java game servers or bitcoin mining one full cpu and 100% of your allocated ram are necessary, but for standard website hosting, rsync backup, monitoring services etc. you usually need just a small part of your resources and for limited time.

    maybe providers could offer 0 overselling for minecraft/torrenting/tor proxy on dedicated nodes with a higher price, and honest overselling at at much lower prices for users that have different needs.

  • @marrco said: but for standard website hosting, rsync backup, monitoring services etc. you usually need just a small part of your resources and for limited time.

    Good point. If you're on the same node with users who runs gameservers.. your site will go slow.. LOL

    My Own Universe | ChatX IRC Network irc.chatx.net:6667
  • @LivingSoul that's why sometimes less is more for me. I check for restriction like no irc, no torrenting, i prefer hosts that offer less traffic and space, i check if the 'owners' are just some kids trying to sell part of new dedi gaming server or a (company/adult/startup) trying to get in the VPS business.

    Providers choose their market. Some take all, some try to appeal to gameserver users other have a different target. I'm also very suspicious of high discounts, 20% is enough. Want more? Prepay 6 months and one is free. Or pay one year and have 2 free months.

    But price and listed resources are just a part of the story. Company background and owners experience can tell you more about the ability to manage overselling. And when my brochure websites are slow and i complain to the provider, they sometimes choose to keep me as a customer (and move gameservers/ircers and other l33t users on a separate node).

  • I agree.. :)

    My Own Universe | ChatX IRC Network irc.chatx.net:6667
  • @Rens said: Xen. We have tested with KVM, but are not getting anywhere near the results we get with Xen. It is improving fast so we are keeping an eye on the developments.

    Xen PV I guess? What about Xen HVM vs KVM?

  • InfinityInfinity Retired Staff

    I'd choose KVM over HVM. PV does have a performance edge over both of those due to less overhead etc.

    我是一个巨魔 (;

  • @bobinfo: Both, especially disk performance was a problem with KVM. On some hypervisors we also did not get proper test results (speeds above what was possible).

  • AldryicAldryic Member
    edited November 2011

    Performance aside, I prefer KVM from a security standpoint. With OpenVZ, all an admin has to do is 'vzctl enter' to get into your VPS as root, or simply browse /vz/private/'ctid'. With KVM, so long as you reset your root pass (or disable root) after provisioning, they would have to SU the container to get into it. Aside from the obvious 'downtime' from this, you can also set on-boot scripts to email you when your VPS starts, etc, to let you know if it's been rebooted.

    BuyVM - OpenVZ & KVM Based / TUN, PPTP, FUSE, SIT & GRE Enabled! / Stallion Control Panel || G+ / FB
  • @Aldryic said: Performance aside, I prefer KVM from a security standpoint. With OpenVZ, all an admin has to do is 'vzctl enter' to get into your VPS as root, or simply browse /vz/private/'ctid'. With KVM, so long as you reset your root pass (or disable root) after provisioning, they would have to SU the container to get into it. Aside from the obvious 'downtime' from this, you can also set on-boot scripts to email you when your VPS starts, etc, to let you know if it's been rebooted.

    Also, if the host does that and then tries to login, it won't bypass most login detection scripts like vzctl enter {ctid} does. But, if you leave the console logged in when you are not using it, then they have an easy way in.

    FreeVPS.us - The oldest post to host VPS provider
  • @dmmcintyre3 said: But, if you leave the console logged in when you are not using it

    Aside from a VPS where I want to block SSH completely, I don't use console at all after the initial setup :P

    BuyVM - OpenVZ & KVM Based / TUN, PPTP, FUSE, SIT & GRE Enabled! / Stallion Control Panel || G+ / FB
  • @rds100 Correction, with OpenVZ there is no overhead.

    OpenVZ will provide the best performance as if it was running outside of it, but it depends on the settings, as well as what's running on the node and it's load

    Daniel.

  • @Rens said: Both, especially disk performance was a problem with KVM. On some hypervisors we also did not get proper test results (speeds above what was possible).

    With KVM the disk can't be a LVM 'partition'? In that case there is no overhead, right?

  • InfinityInfinity Retired Staff
    edited November 2011

    @bobinfo said: In that case there is no overhead, right?

    No noticable overhead.

    我是一个巨魔 (;

  • ghostghost Member
    edited November 2011

    from 2.6.39 / 3.0 , XEN inside to kernel too, you can choice to keep use XEN.

  • vtwvtw Member

    Is it true that you'll use less RAM on KVM than on OpenVZ when running the same programs? Why/How if true?

  • @vtw said: Is it true that you'll use less RAM on KVM than on OpenVZ when running the same programs? Why/How if true?

    Sometimes.

    OpenVZ used to allocate RAM based on the virtual size, not based on what was actually being used. This bug/derp is addressed in the new 2.6.32 based kernels.

    In 2.6.32 RAM is allocated the same was as KVM/XEN/vmware/etc

    Francisco

    BuyVM - OpenVZ & KVM Based / TUN, PPTP, FUSE, SIT & GRE Enabled! / Stallion Control Panel
  • it depens on what you want to run on it

    i personal preffer XenServer ( bare metal based on Xen) because ram overselling is not possible ( disk overselling is not possible eather)

    it depends to what you like to do, do you want to spend on dedicated harware and provide true virtual dedicated servers ( where everything is 100% isolated from each other) or do you preffer to run things in a container ( shared ram with allocated max ram usage ?)

    Xen allocates the ram and isolate the ram so only that certain vps can use the assigned ram for 100% when openvz use a container and let you use up to XX ram , but the ram stays shared (allows overselling as the ram is always free )

    so to give a example about this if you got 3 vps servers with each 1GB ram , your node is 4GB ram then on Xen you got 1GB ram free that get used by the core for stability, and 3GB ram that get serperate used by the vm's

    on Openvz you still got 4GB ram free that get used by the system and the vm's just take up to 1GB ram as soon they need it , the first who need it get it that makes it that on openvz you can use 3 vps servers with 2GB ram and still works perfect

    only problem , if all 3 vps servers are requesting for 2GB ram at the same time then you get a big crash ... thats what overselling does

    so to get back on the normal request , i preffer Xen because of his dedicated ram assignment

    Greetings From PowerChaos

  • Xen is far better than OpenVZ as all the resource that a VM have, are allocated dedicatedly to the VM. So basically, the RAM and disk space you have in your Xen VM, Well, although not 100% is dedicated resources

    Affordable VPS provider with Excellent Help-desk Support with 24/7 Live-chat

  • smansman Member

    There is so much bad info out there about this. It's hard to summarize without having to get into the technical details but I will try.

    First of all for performance OpenVZ wins hands down in almost (and perhaps all) cases. If you don't believe me prove it to yourself. People kept saying kvm will get better and it has but it's still no where near OpenVZ for performance and low overhead and never will be. That is a hard fact and comes down to the way the virtualization works.

    Yes you can oversell with OpenVZ but looking at it the other way, it's a much more efficient use of hardware and one way or another that cost savings get passed on to the customer in a highly competitive environment. With KVM things like unused storage are wasted.

    Another big one about OpenVZ that is not often mentioned. Because each container does not need to run it's own kernel and associated hardware hooks/apps/caching etc. the amount of memory available to the user on a 512MB OpenVZ container is actually quite a bit higher than on a KVM container. The difference is about 100MB in my testing using CentOS 6 64bit. Again, much more efficient use of hardware only this time it benefits the user.

  • For the love of god.

    For most providers here, it's not going to MATTER what hypervisor is used. It matters how they police abuse.

  • @Rallias said: For most providers here, it's not going to MATTER what hypervisor is used. It matters how they police abuse.

    Well, to a degree. I saw that outgoing Dos peaks at 700 k pps on KVM and about 1.4 mil on OVZ on same hardware. That may have to do with how networking is handled but also with virtualization overhead, even with virtio emulated nics.

    That being said, OVZ should be fastest, Xen pv close and KVM slowest about same as Xen HVM. We will see the new xen hybrid versions how are they doing to replace HVM, I hope the performance gain will be solid and we can have bsd/windows/whatever without much hassle.

    Mind you, bsd was possible on xen PV before, but not really for the masses.

    I am only representing myself :)

Sign In or Register to comment.