Re: [libvirt] [Qemu-devel] [RFC] block I/O throttling: how to enable in libvirt
On Fri, Sep 2, 2011 at 3:09 AM, Zhi Yong Wu wu...@linux.vnet.ibm.com wrote: On Thu, Sep 01, 2011 at 09:11:49AM +0100, Stefan Hajnoczi wrote: Date: Thu, 1 Sep 2011 09:11:49 +0100 From: Stefan Hajnoczi stefa...@gmail.com To: Zhi Yong Wu wu...@linux.vnet.ibm.com Message-ID: 20110901081149.GB14245@stefanha-thinkpad.localdomain References: 20110901050531.gb17...@f15.cn.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: 20110901050531.gb17...@f15.cn.ibm.com User-Agent: Mutt/1.5.21 (2010-09-15) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-Received-From: 74.125.82.173 Cc: libvir-list@redhat.com, guijianf...@cn.fujitsu.com, a...@us.ibm.com, qemu-de...@nongnu.org, zwu.ker...@gmail.com, hu...@cn.fujitsu.com Subject: Re: [Qemu-devel] [RFC] block I/O throttling: how to enable in libvirt X-BeenThere: qemu-de...@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: https://lists.nongnu.org/mailman/options/qemu-devel, mailto:qemu-devel-requ...@nongnu.org?subject=unsubscribe List-Archive: /archive/html/qemu-devel List-Post: mailto:qemu-de...@nongnu.org List-Help: mailto:qemu-devel-requ...@nongnu.org?subject=help List-Subscribe: https://lists.nongnu.org/mailman/listinfo/qemu-devel, mailto:qemu-devel-requ...@nongnu.org?subject=subscribe X-Mailman-Copy: yes Errors-To: qemu-devel-bounces+wuzhy=linux.vnet.ibm@nongnu.org Sender: qemu-devel-bounces+wuzhy=linux.vnet.ibm@nongnu.org x-cbid: 11090108-7282---010970B0 X-IBM-ISS-SpamDetectors: Score=0; BY=0; FL=0; FP=0; FZ=0; HX=0; KW=0; PH=0; SC=0; ST=0; TS=0; UL=0; ISC= X-IBM-ISS-DetailInfo: BY=3.0211; HX=3.0168; KW=3.0007; PH=3.0001; SC=3.0001; SDB=6.00067104; UDB=6.00020326; UTC=2011-09-01 08:12:15 X-Xagent-From: stefa...@gmail.com X-Xagent-To: wu...@linux.vnet.ibm.com X-Xagent-Gateway: vmsdvm6.vnet.ibm.com (XAGENTU5 at VMSDVM6) On Thu, Sep 01, 2011 at 01:05:31PM +0800, Zhi Yong Wu wrote: On Wed, Aug 31, 2011 at 08:18:19AM +0100, Stefan Hajnoczi wrote: On Tue, Aug 30, 2011 at 2:46 PM, Adam Litke a...@us.ibm.com wrote: On Tue, Aug 30, 2011 at 09:53:33AM +0100, Stefan Hajnoczi wrote: I/O throttling can be applied independently to each -drive attached to a guest and supports throughput/iops limits. For more information on this QEMU feature and a comparison with blkio-controller, see Ryan Harper's KVM Forum 2011 presentation: http://www.linux-kvm.org/wiki/images/7/72/2011-forum-keep-a-limit-on-it-io-throttling-in-qemu.pdf From the presentation, it seems that both the cgroups method the the qemu method offer comparable control (assuming a block device) so it might possible to apply either method from the same API in a transparent manner. Am I correct or are we suggesting that the Qemu throttling approach should always be used for Qemu domains? QEMU I/O throttling does not provide a proportional share mechanism. So you cannot assign weights to VMs and let them receive a fraction of the available disk time. That is only supported by cgroups blkio-controller because it requires a global view which QEMU does not have. So I think the two are complementary: If proportional share should be used on a host block device, use cgroups blkio-controller. Otherwise use QEMU I/O throttling. Stefan, Do you agree with introducing one new libvirt command blkiothrottle now? If so, i will work on the code draft to make it work. No, I think that the blkiotune command should be extended to support QEMU I/O throttling. This is not new functionality, we already have cgroups blkio-controller support today. Therefore I think it makes sense to keep a unified interface instead of adding a new command. QEMU I/O throttling currently don't support those options of blkiotune, such as --live, --config and --current.If those bps/iops settings are modified, it will immediately take effect. The --live, --config, and --current options are implemented inside libvirt and do not require hypervisor support. Take a look at src/qemu/qemu_driver.c:qemuDomainSetBlkioParameters() to see how these options are implemented for blkiotune today. Stefan -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [Qemu-devel] [RFC] block I/O throttling: how to enable in libvirt
On Fri, Sep 02, 2011 at 09:50:42AM +0100, Stefan Hajnoczi wrote: Date: Fri, 2 Sep 2011 09:50:42 +0100 Message-ID: CAJSP0QWc9OcOKxG3jGgYD3r5f=2fqv3snvcrarc2tm0ymp+...@mail.gmail.com Subject: Re: [Qemu-devel] [RFC] block I/O throttling: how to enable in libvirt From: Stefan Hajnoczi stefa...@gmail.com To: Zhi Yong Wu wu...@linux.vnet.ibm.com Cc: libvir-list@redhat.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Brightmail-Tracker: AA== X-Xagent-From: stefa...@gmail.com X-Xagent-To: wu...@linux.vnet.ibm.com X-Xagent-Gateway: vmsdvm4.vnet.ibm.com (XAGENTU5 at VMSDVM4) On Fri, Sep 2, 2011 at 3:09 AM, Zhi Yong Wu wu...@linux.vnet.ibm.com wrote: On Thu, Sep 01, 2011 at 09:11:49AM +0100, Stefan Hajnoczi wrote: Date: Thu, 1 Sep 2011 09:11:49 +0100 From: Stefan Hajnoczi stefa...@gmail.com To: Zhi Yong Wu wu...@linux.vnet.ibm.com Message-ID: 20110901081149.GB14245@stefanha-thinkpad.localdomain References: 20110901050531.gb17...@f15.cn.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: 20110901050531.gb17...@f15.cn.ibm.com User-Agent: Mutt/1.5.21 (2010-09-15) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-Received-From: 74.125.82.173 Cc: libvir-list@redhat.com, guijianf...@cn.fujitsu.com, a...@us.ibm.com, qemu-de...@nongnu.org, zwu.ker...@gmail.com, hu...@cn.fujitsu.com Subject: Re: [Qemu-devel] [RFC] block I/O throttling: how to enable in libvirt X-BeenThere: qemu-de...@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: https://lists.nongnu.org/mailman/options/qemu-devel, mailto:qemu-devel-requ...@nongnu.org?subject=unsubscribe List-Archive: /archive/html/qemu-devel List-Post: mailto:qemu-de...@nongnu.org List-Help: mailto:qemu-devel-requ...@nongnu.org?subject=help List-Subscribe: https://lists.nongnu.org/mailman/listinfo/qemu-devel, mailto:qemu-devel-requ...@nongnu.org?subject=subscribe X-Mailman-Copy: yes Errors-To: qemu-devel-bounces+wuzhy=linux.vnet.ibm@nongnu.org Sender: qemu-devel-bounces+wuzhy=linux.vnet.ibm@nongnu.org x-cbid: 11090108-7282---010970B0 X-IBM-ISS-SpamDetectors: Score=0; BY=0; FL=0; FP=0; FZ=0; HX=0; KW=0; PH=0; SC=0; ST=0; TS=0; UL=0; ISC= X-IBM-ISS-DetailInfo: BY=3.0211; HX=3.0168; KW=3.0007; PH=3.0001; SC=3.0001; SDB=6.00067104; UDB=6.00020326; UTC=2011-09-01 08:12:15 X-Xagent-From: stefa...@gmail.com X-Xagent-To: wu...@linux.vnet.ibm.com X-Xagent-Gateway: vmsdvm6.vnet.ibm.com (XAGENTU5 at VMSDVM6) On Thu, Sep 01, 2011 at 01:05:31PM +0800, Zhi Yong Wu wrote: On Wed, Aug 31, 2011 at 08:18:19AM +0100, Stefan Hajnoczi wrote: On Tue, Aug 30, 2011 at 2:46 PM, Adam Litke a...@us.ibm.com wrote: On Tue, Aug 30, 2011 at 09:53:33AM +0100, Stefan Hajnoczi wrote: I/O throttling can be applied independently to each -drive attached to a guest and supports throughput/iops limits. For more information on this QEMU feature and a comparison with blkio-controller, see Ryan Harper's KVM Forum 2011 presentation: http://www.linux-kvm.org/wiki/images/7/72/2011-forum-keep-a-limit-on-it-io-throttling-in-qemu.pdf From the presentation, it seems that both the cgroups method the the qemu method offer comparable control (assuming a block device) so it might possible to apply either method from the same API in a transparent manner. Am I correct or are we suggesting that the Qemu throttling approach should always be used for Qemu domains? QEMU I/O throttling does not provide a proportional share mechanism. So you cannot assign weights to VMs and let them receive a fraction of the available disk time. That is only supported by cgroups blkio-controller because it requires a global view which QEMU does not have. So I think the two are complementary: If proportional share should be used on a host block device, use cgroups blkio-controller. Otherwise use QEMU I/O throttling. Stefan, Do you agree with introducing one new libvirt command blkiothrottle now? If so, i will work on the code draft to make it work. No, I think that the blkiotune command should be extended to support QEMU I/O throttling. This is not new functionality, we already have cgroups blkio-controller support today. Therefore I think it makes sense to keep a unified interface instead of adding a new command. QEMU I/O throttling currently don't support those options of blkiotune, such as --live, --config and --current.If those bps/iops settings are modified, it will immediately take effect. The --live, --config, and --current options are implemented inside libvirt and do not require hypervisor support. Take a look at src/qemu/qemu_driver.c:qemuDomainSetBlkioParameters() to see how these options are implemented for blkiotune today. I have understood this, thanks. BTW: i have seen your comments against block I/O
Re: [libvirt] [Qemu-devel] [RFC] block I/O throttling: how to enable in libvirt
On Fri, Sep 02, 2011 at 09:16:59AM +0800, Gui Jianfeng wrote: Message-ID: 4e602e8b.6010...@cn.fujitsu.com Date: Fri, 02 Sep 2011 09:16:59 +0800 From: Gui Jianfeng guijianf...@cn.fujitsu.com User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:6.0) Gecko/20110812 Thunderbird/6.0 MIME-Version: 1.0 To: Stefan Hajnoczi stefa...@gmail.com, Zhi Yong Wu wu...@linux.vnet.ibm.com References: 20110901050531.gb17...@f15.cn.ibm.com 20110901081149.GB14245@stefanha-thinkpad.localdomain In-Reply-To: 20110901081149.GB14245@stefanha-thinkpad.localdomain X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-09-02 09:15:49, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-09-02 09:15:52, Serialize complete at 2011-09-02 09:15:52 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 X-detected-operating-system: by eggs.gnu.org: FreeBSD 6.x (1) X-Received-From: 222.73.24.84 Cc: libvir-list@redhat.com, hu...@cn.fujitsu.com, qemu-de...@nongnu.org, zwu.ker...@gmail.com, a...@us.ibm.com Subject: Re: [Qemu-devel] [RFC] block I/O throttling: how to enable in libvirt X-BeenThere: qemu-de...@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: https://lists.nongnu.org/mailman/options/qemu-devel, mailto:qemu-devel-requ...@nongnu.org?subject=unsubscribe List-Archive: /archive/html/qemu-devel List-Post: mailto:qemu-de...@nongnu.org List-Help: mailto:qemu-devel-requ...@nongnu.org?subject=help List-Subscribe: https://lists.nongnu.org/mailman/listinfo/qemu-devel, mailto:qemu-devel-requ...@nongnu.org?subject=subscribe X-Mailman-Copy: yes Errors-To: qemu-devel-bounces+wuzhy=linux.vnet.ibm@nongnu.org Sender: qemu-devel-bounces+wuzhy=linux.vnet.ibm@nongnu.org X-Brightmail-Tracker: AA== X-Xagent-From: guijianf...@cn.fujitsu.com X-Xagent-To: wu...@linux.vnet.ibm.com X-Xagent-Gateway: vmsdvm9.vnet.ibm.com (XAGENTU at VMSDVM9) On 2011-9-1 16:11, Stefan Hajnoczi wrote: On Thu, Sep 01, 2011 at 01:05:31PM +0800, Zhi Yong Wu wrote: On Wed, Aug 31, 2011 at 08:18:19AM +0100, Stefan Hajnoczi wrote: On Tue, Aug 30, 2011 at 2:46 PM, Adam Litke a...@us.ibm.com wrote: On Tue, Aug 30, 2011 at 09:53:33AM +0100, Stefan Hajnoczi wrote: I/O throttling can be applied independently to each -drive attached to a guest and supports throughput/iops limits. For more information on this QEMU feature and a comparison with blkio-controller, see Ryan Harper's KVM Forum 2011 presentation: http://www.linux-kvm.org/wiki/images/7/72/2011-forum-keep-a-limit-on-it-io-throttling-in-qemu.pdf From the presentation, it seems that both the cgroups method the the qemu method offer comparable control (assuming a block device) so it might possible to apply either method from the same API in a transparent manner. Am I correct or are we suggesting that the Qemu throttling approach should always be used for Qemu domains? QEMU I/O throttling does not provide a proportional share mechanism. So you cannot assign weights to VMs and let them receive a fraction of the available disk time. That is only supported by cgroups blkio-controller because it requires a global view which QEMU does not have. So I think the two are complementary: If proportional share should be used on a host block device, use cgroups blkio-controller. Otherwise use QEMU I/O throttling. Stefan, Do you agree with introducing one new libvirt command blkiothrottle now? If so, i will work on the code draft to make it work. No, I think that the blkiotune command should be extended to support QEMU I/O throttling. This is not new functionality, we already have cgroups blkio-controller support today. Therefore I think it makes sense to keep a unified interface instead of adding a new command. Agreed. Proportional controlling interfaces and throttling interfaces are all the same cgroup subsystem. So Just extend blkiotune to add new options to support throttling tuning. Hi, Gui, QEMU block I/O throttling is not relative to cgroup subsystem, i think. anyway, thanks for your sugguests. Regards, Zhi Yong Wu Thanks, Gui Stefan -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [Qemu-devel] [RFC] block I/O throttling: how to enable in libvirt
On Thu, Sep 01, 2011 at 09:11:49AM +0100, Stefan Hajnoczi wrote: Date: Thu, 1 Sep 2011 09:11:49 +0100 From: Stefan Hajnoczi stefa...@gmail.com To: Zhi Yong Wu wu...@linux.vnet.ibm.com Message-ID: 20110901081149.GB14245@stefanha-thinkpad.localdomain References: 20110901050531.gb17...@f15.cn.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: 20110901050531.gb17...@f15.cn.ibm.com User-Agent: Mutt/1.5.21 (2010-09-15) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-Received-From: 74.125.82.173 Cc: libvir-list@redhat.com, guijianf...@cn.fujitsu.com, a...@us.ibm.com, qemu-de...@nongnu.org, zwu.ker...@gmail.com, hu...@cn.fujitsu.com Subject: Re: [Qemu-devel] [RFC] block I/O throttling: how to enable in libvirt X-BeenThere: qemu-de...@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: https://lists.nongnu.org/mailman/options/qemu-devel, mailto:qemu-devel-requ...@nongnu.org?subject=unsubscribe List-Archive: /archive/html/qemu-devel List-Post: mailto:qemu-de...@nongnu.org List-Help: mailto:qemu-devel-requ...@nongnu.org?subject=help List-Subscribe: https://lists.nongnu.org/mailman/listinfo/qemu-devel, mailto:qemu-devel-requ...@nongnu.org?subject=subscribe X-Mailman-Copy: yes Errors-To: qemu-devel-bounces+wuzhy=linux.vnet.ibm@nongnu.org Sender: qemu-devel-bounces+wuzhy=linux.vnet.ibm@nongnu.org x-cbid: 11090108-7282---010970B0 X-IBM-ISS-SpamDetectors: Score=0; BY=0; FL=0; FP=0; FZ=0; HX=0; KW=0; PH=0; SC=0; ST=0; TS=0; UL=0; ISC= X-IBM-ISS-DetailInfo: BY=3.0211; HX=3.0168; KW=3.0007; PH=3.0001; SC=3.0001; SDB=6.00067104; UDB=6.00020326; UTC=2011-09-01 08:12:15 X-Xagent-From: stefa...@gmail.com X-Xagent-To: wu...@linux.vnet.ibm.com X-Xagent-Gateway: vmsdvm6.vnet.ibm.com (XAGENTU5 at VMSDVM6) On Thu, Sep 01, 2011 at 01:05:31PM +0800, Zhi Yong Wu wrote: On Wed, Aug 31, 2011 at 08:18:19AM +0100, Stefan Hajnoczi wrote: On Tue, Aug 30, 2011 at 2:46 PM, Adam Litke a...@us.ibm.com wrote: On Tue, Aug 30, 2011 at 09:53:33AM +0100, Stefan Hajnoczi wrote: I/O throttling can be applied independently to each -drive attached to a guest and supports throughput/iops limits. For more information on this QEMU feature and a comparison with blkio-controller, see Ryan Harper's KVM Forum 2011 presentation: http://www.linux-kvm.org/wiki/images/7/72/2011-forum-keep-a-limit-on-it-io-throttling-in-qemu.pdf From the presentation, it seems that both the cgroups method the the qemu method offer comparable control (assuming a block device) so it might possible to apply either method from the same API in a transparent manner. Am I correct or are we suggesting that the Qemu throttling approach should always be used for Qemu domains? QEMU I/O throttling does not provide a proportional share mechanism. So you cannot assign weights to VMs and let them receive a fraction of the available disk time. That is only supported by cgroups blkio-controller because it requires a global view which QEMU does not have. So I think the two are complementary: If proportional share should be used on a host block device, use cgroups blkio-controller. Otherwise use QEMU I/O throttling. Stefan, Do you agree with introducing one new libvirt command blkiothrottle now? If so, i will work on the code draft to make it work. No, I think that the blkiotune command should be extended to support QEMU I/O throttling. This is not new functionality, we already have cgroups blkio-controller support today. Therefore I think it makes sense to keep a unified interface instead of adding a new command. QEMU I/O throttling currently don't support those options of blkiotune, such as --live, --config and --current.If those bps/iops settings are modified, it will immediately take effect. Regards, Zhi Yong Wu Stefan -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
Re: [libvirt] [Qemu-devel] [RFC] block I/O throttling: how to enable in libvirt
On 2011-9-2 9:58, Zhi Yong Wu wrote: On Fri, Sep 02, 2011 at 09:16:59AM +0800, Gui Jianfeng wrote: Message-ID: 4e602e8b.6010...@cn.fujitsu.com Date: Fri, 02 Sep 2011 09:16:59 +0800 From: Gui Jianfeng guijianf...@cn.fujitsu.com User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:6.0) Gecko/20110812 Thunderbird/6.0 MIME-Version: 1.0 To: Stefan Hajnoczi stefa...@gmail.com, Zhi Yong Wu wu...@linux.vnet.ibm.com References: 20110901050531.gb17...@f15.cn.ibm.com 20110901081149.GB14245@stefanha-thinkpad.localdomain In-Reply-To: 20110901081149.GB14245@stefanha-thinkpad.localdomain X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-09-02 09:15:49,Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25,2010) at 2011-09-02 09:15:52, Serialize complete at 2011-09-02 09:15:52 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 X-detected-operating-system: by eggs.gnu.org: FreeBSD 6.x (1) X-Received-From: 222.73.24.84 Cc: libvir-list@redhat.com, hu...@cn.fujitsu.com, qemu-de...@nongnu.org, zwu.ker...@gmail.com, a...@us.ibm.com Subject: Re: [Qemu-devel] [RFC] block I/O throttling: how to enable in libvirt X-BeenThere: qemu-de...@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: https://lists.nongnu.org/mailman/options/qemu-devel, mailto:qemu-devel-requ...@nongnu.org?subject=unsubscribe List-Archive: /archive/html/qemu-devel List-Post: mailto:qemu-de...@nongnu.org List-Help: mailto:qemu-devel-requ...@nongnu.org?subject=help List-Subscribe: https://lists.nongnu.org/mailman/listinfo/qemu-devel, mailto:qemu-devel-requ...@nongnu.org?subject=subscribe X-Mailman-Copy: yes Errors-To: qemu-devel-bounces+wuzhy=linux.vnet.ibm@nongnu.org Sender: qemu-devel-bounces+wuzhy=linux.vnet.ibm@nongnu.org X-Brightmail-Tracker: AA== X-Xagent-From: guijianf...@cn.fujitsu.com X-Xagent-To: wu...@linux.vnet.ibm.com X-Xagent-Gateway: vmsdvm9.vnet.ibm.com (XAGENTU at VMSDVM9) On 2011-9-1 16:11, Stefan Hajnoczi wrote: On Thu, Sep 01, 2011 at 01:05:31PM +0800, Zhi Yong Wu wrote: On Wed, Aug 31, 2011 at 08:18:19AM +0100, Stefan Hajnoczi wrote: On Tue, Aug 30, 2011 at 2:46 PM, Adam Litke a...@us.ibm.com wrote: On Tue, Aug 30, 2011 at 09:53:33AM +0100, Stefan Hajnoczi wrote: I/O throttling can be applied independently to each -drive attached to a guest and supports throughput/iops limits. For more information on this QEMU feature and a comparison with blkio-controller, see Ryan Harper's KVM Forum 2011 presentation: http://www.linux-kvm.org/wiki/images/7/72/2011-forum-keep-a-limit-on-it-io-throttling-in-qemu.pdf From the presentation, it seems that both the cgroups method the the qemu method offer comparable control (assuming a block device) so it might possible to apply either method from the same API in a transparent manner. Am I correct or are we suggesting that the Qemu throttling approach should always be used for Qemu domains? QEMU I/O throttling does not provide a proportional share mechanism. So you cannot assign weights to VMs and let them receive a fraction of the available disk time. That is only supported by cgroups blkio-controller because it requires a global view which QEMU does not have. So I think the two are complementary: If proportional share should be used on a host block device, use cgroups blkio-controller. Otherwise use QEMU I/O throttling. Stefan, Do you agree with introducing one new libvirt command blkiothrottle now? If so, i will work on the code draft to make it work. No, I think that the blkiotune command should be extended to support QEMU I/O throttling. This is not new functionality, we already have cgroups blkio-controller support today. Therefore I think it makes sense to keep a unified interface instead of adding a new command. Agreed. Proportional controlling interfaces and throttling interfaces are all the same cgroup subsystem. So Just extend blkiotune to add new options to support throttling tuning. Hi, Gui, QEMU block I/O throttling is not relative to cgroup subsystem, i think. anyway, thanks for your sugguests. Ahh, I misunderstand you before. I thought you mentioned the blkio cgroup throttling interfaces. Ok, I think QEmu I/O throttling has similar semantic with blkio cgroup. So extending blkiotune command is preferred, IMHO. Thanks, Gui Regards, Zhi Yong Wu Thanks, Gui Stefan -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
