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Posted to users@cloudstack.apache.org by Benjamin Naber <be...@coders-area.de> on 2018/08/03 14:05:13 UTC
slow performance CEPH RBD on KVM
Hi @all,
ive setup a Ceph Cluster in combination with KVM Hosts. If i benchmark ceph rbd performance from Hypervisor itself i got 10 times higher performance than from using a cloudstack created guest-vm.
are there any recommendet settings for KVM Hosts in cloudstack or KVM using with ceph rbd ?
kind regards
Ben
Re: Solved: slow performance CEPH RBD on KVM
Posted by Andrija Panic <an...@gmail.com>.
Cool, I didn't consider this as a variable :)
IDE works extremely slow indeed... anyway, make sure to also have RBD
caching on KVM side.
Cheers
On Mon, Aug 6, 2018, 14:51 Benjamin Naber <be...@coders-area.de>
wrote:
> Hi Andrija,
>
> i figured out the problem. templates should be created as OS: Other PV
> Virtio-SCSI (64-bit) otherwise, vm disk will created as an IDE Device.
>
> Afther changing the setting i got my Performance and a well working
> environment.
>
>
> Kind regards
>
> Ben
>
> >
> > Andrija Panic <an...@gmail.com> hat am 5. August 2018 um
> 11:05 geschrieben:
> >
> > Hi,
> >
> > Google "enable rbd cache on KVM" - this is supposed to enable write
> back
> > cache if client OS sends proper flush commands (i.e. linux kernel
> newer
> > than 3.0) - will NOT help with reads, obviously...
> >
> > For rest, there can be done some tunning, but expect no miracle.
> >
> > You didn't specify ceph cluster details, journals setup, etc - would
> be
> > useful to know, then KVM host version, etc.
> >
> > Cheers
> >
> > On Fri, Aug 3, 2018, 16:05 Benjamin Naber <
> benjamin.naber@coders-area.de>
> > wrote:
> >
> > > >
> > > Hi @all,
> > >
> > > ive setup a Ceph Cluster in combination with KVM Hosts. If i
> benchmark
> > > ceph rbd performance from Hypervisor itself i got 10 times
> higher
> > > performance than from using a cloudstack created guest-vm.
> > > are there any recommendet settings for KVM Hosts in cloudstack
> or KVM
> > > using with ceph rbd ?
> > >
> > > kind regards
> > > Ben
> > >
> > > >
>
Solved: slow performance CEPH RBD on KVM
Posted by Benjamin Naber <be...@coders-area.de>.
Hi Andrija,
i figured out the problem. templates should be created as OS: Other PV Virtio-SCSI (64-bit) otherwise, vm disk will created as an IDE Device.
Afther changing the setting i got my Performance and a well working environment.
Kind regards
Ben
>
> Andrija Panic <an...@gmail.com> hat am 5. August 2018 um 11:05 geschrieben:
>
> Hi,
>
> Google "enable rbd cache on KVM" - this is supposed to enable write back
> cache if client OS sends proper flush commands (i.e. linux kernel newer
> than 3.0) - will NOT help with reads, obviously...
>
> For rest, there can be done some tunning, but expect no miracle.
>
> You didn't specify ceph cluster details, journals setup, etc - would be
> useful to know, then KVM host version, etc.
>
> Cheers
>
> On Fri, Aug 3, 2018, 16:05 Benjamin Naber <be...@coders-area.de>
> wrote:
>
> > >
> > Hi @all,
> >
> > ive setup a Ceph Cluster in combination with KVM Hosts. If i benchmark
> > ceph rbd performance from Hypervisor itself i got 10 times higher
> > performance than from using a cloudstack created guest-vm.
> > are there any recommendet settings for KVM Hosts in cloudstack or KVM
> > using with ceph rbd ?
> >
> > kind regards
> > Ben
> >
> > >
Re: slow performance CEPH RBD on KVM
Posted by Andrija Panic <an...@gmail.com>.
Hi,
Google "enable rbd cache on KVM" - this is supposed to enable write back
cache if client OS sends proper flush commands (i.e. linux kernel newer
than 3.0) - will NOT help with reads, obviously...
For rest, there can be done some tunning, but expect no miracle.
You didn't specify ceph cluster details, journals setup, etc - would be
useful to know, then KVM host version, etc.
Cheers
On Fri, Aug 3, 2018, 16:05 Benjamin Naber <be...@coders-area.de>
wrote:
> Hi @all,
>
> ive setup a Ceph Cluster in combination with KVM Hosts. If i benchmark
> ceph rbd performance from Hypervisor itself i got 10 times higher
> performance than from using a cloudstack created guest-vm.
> are there any recommendet settings for KVM Hosts in cloudstack or KVM
> using with ceph rbd ?
>
> kind regards
> Ben
>