Equivalent of vmware SIOC (Storage IO Control) in KVM

Equivalent of vmware SIOC (Storage IO Control) in KVM

[Soumendu Satapathy (sosatapa)]

Do we have an equivalent of vmware SIOC like feature in KVM?

- soumendu

Re: Equivalent of vmware SIOC (Storage IO Control) in KVM

[Paolo Bonzini]

Il 12/10/2013 08:09, Soumendu Satapathy (sosatapa) ha scritto:
> Do we have an equivalent of vmware SIOC like feature in KVM?

Yes, you have two choices:

1) use cgroups to throttle I/O at the level of the host disk (i.e.
multiple virtual disks stored on the same disk share the limit).  If
you're using libvirt, add the <blkiotune> element to the definition of
the virtual machine.

2) enable I/O throttling in QEMU, to apply limits at the level of the
guest disk.  If you're using libvirt, add the "iotune" element within
the <disk> element in the definition of the virtual machine.

Both are documented at http://libvirt.org/formatdomain.html (search for
blkiotune and iotune).

Paolo

Re: Equivalent of vmware SIOC (Storage IO Control) in KVM

[Andrey Korolyov]

Hello,

By the way, is there plans to enhance qemu I/O throttling to able to
swallow peaks or to apply various disciplines? Current one-second flat
discipline seemingly is not enough for uneven workloads especially
when there is no alternative like cgroups for nbd usage.

Thanks!

On Sun, Oct 13, 2013 at 5:26 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> 2) enable I/O throttling in QEMU, to apply limits at the level of the
> guest disk.  If you're using libvirt, add the "iotune" element within
> the <disk> element in the definition of the virtual machine.

Re: Equivalent of vmware SIOC (Storage IO Control) in KVM

[Fam Zheng]

On Mon, 10/14 02:13, Andrey Korolyov wrote:
> Hello,
> 
> By the way, is there plans to enhance qemu I/O throttling to able to
> swallow peaks or to apply various disciplines? Current one-second flat
> discipline seemingly is not enough for uneven workloads especially
> when there is no alternative like cgroups for nbd usage.
> 

Hi,

In current upstream master there are improvements on throttling (actually a
total rework), which added burst limits with new options of bps_max, iops_max,
etc.

Fam

RE: Equivalent of vmware SIOC (Storage IO Control) in KVM

[Wangshen (Peter)]

on Sunday, October 13, 2013 9:27 PM, Paolo Bonzini wrote:
> Il 12/10/2013 08:09, Soumendu Satapathy (sosatapa) ha scritto:
> > Do we have an equivalent of vmware SIOC like feature in KVM?
> 
> Yes, you have two choices:
> 
> 1) use cgroups to throttle I/O at the level of the host disk (i.e.
> multiple virtual disks stored on the same disk share the limit).  If you're
> using libvirt, add the <blkiotune> element to the definition of the virtual
> machine.
> 
> 2) enable I/O throttling in QEMU, to apply limits at the level of the guest
> disk.  If you're using libvirt, add the "iotune" element within the <disk>
> element in the definition of the virtual machine.
> 
> Both are documented at http://libvirt.org/formatdomain.html (search for
> blkiotune and iotune).

Both "blkiotune" and "iotune" are only take effect on one same host.
How to throttle I/O across multiple host with shared storage devices?

Re: Equivalent of vmware SIOC (Storage IO Control) in KVM

[Fam Zheng]

On Mon, 10/14 02:18, Wangshen (Peter) wrote:
> 
> 
> on Sunday, October 13, 2013 9:27 PM, Paolo Bonzini wrote:
> > Il 12/10/2013 08:09, Soumendu Satapathy (sosatapa) ha scritto:
> > > Do we have an equivalent of vmware SIOC like feature in KVM?
> > 
> > Yes, you have two choices:
> > 
> > 1) use cgroups to throttle I/O at the level of the host disk (i.e.
> > multiple virtual disks stored on the same disk share the limit).  If you're
> > using libvirt, add the <blkiotune> element to the definition of the virtual
> > machine.
> > 
> > 2) enable I/O throttling in QEMU, to apply limits at the level of the guest
> > disk.  If you're using libvirt, add the "iotune" element within the <disk>
> > element in the definition of the virtual machine.
> > 
> > Both are documented at http://libvirt.org/formatdomain.html (search for
> > blkiotune and iotune).
> 
> Both "blkiotune" and "iotune" are only take effect on one same host.
> How to throttle I/O across multiple host with shared storage devices?
> 

Depending on how you use the shared storage, I think you could:

1) Throttle disk/network IO on the shared device with cgroups.

2) Set throttle limit (iotune) on each domain.

Thanks,

Fam

Re: Equivalent of vmware SIOC (Storage IO Control) in KVM

[Paolo Bonzini]

Il 14/10/2013 00:13, Andrey Korolyov ha scritto:
> Hello,
> 
> By the way, is there plans to enhance qemu I/O throttling to able to
> swallow peaks or to apply various disciplines? Current one-second flat
> discipline seemingly is not enough for uneven workloads especially
> when there is no alternative like cgroups for nbd usage.

As Fam said, QEMU 1.7 will support burst throttling.  I'm not sure what
the plans are for adding support to libvirt.

Paolo