[libvirt] [PATCHv2 37/62] qemu: process: Setup disk io throttling for -blockdev
Does this libvirt throttling support “chained throttle filters” for single disk described in QEMU doc: https://github.com/qemu/qemu/blob/master/docs/throttle.txt (“The 'throttle' block filter”)
On Mon, Oct 16, 2023 at 13:36:42 +0000, Chun Feng Wu wrote:
Does this libvirt throttling support “chained throttle filters” for single disk described in QEMU doc: https://github.com/qemu/qemu/blob/master/docs/throttle.txt (“The 'throttle' block filter”)
No, libvirt currently still uses the older approach by using 'block_set_io_throttle' QMP command. This was used at the beginning because the 'throttle' layer was not yet ready at the point when libvirt adopted -blockdev. It is sufficient for the throttling options that are currently configurable via libvirt's XML. Note that to use the full potential of the throttle groups and hierarchical throttling will require significant re-engineering of the XML configuration of throttling.
Thanks for your info! Currently, the iotune in libvirt’s xml indeed works well, BTW, is there any plan for such “re-engineering”? From: Peter Krempa <pkrempa@redhat.com> Date: Monday, October 16, 2023 at 21:53 To: Chun Feng Wu <wucf@cn.ibm.com> Cc: libvir-list@redhat.com <libvir-list@redhat.com> Subject: [EXTERNAL] Re: [libvirt] [PATCHv2 37/62] qemu: process: Setup disk io throttling for -blockdev On Mon, Oct 16, 2023 at 13:36:42 +0000, Chun Feng Wu wrote:
Does this libvirt throttling support “chained throttle filters” for single disk described in QEMU doc: https://github.com/qemu/qemu/blob/master/docs/throttle.txt (“The 'throttle' block filter”)
No, libvirt currently still uses the older approach by using 'block_set_io_throttle' QMP command. This was used at the beginning because the 'throttle' layer was not yet ready at the point when libvirt adopted -blockdev. It is sufficient for the throttling options that are currently configurable via libvirt's XML. Note that to use the full potential of the throttle groups and hierarchical throttling will require significant re-engineering of the XML configuration of throttling.
On Mon, Oct 16, 2023 at 14:19:08 +0000, Chun Feng Wu wrote:
Thanks for your info! Currently, the iotune in libvirt’s xml indeed works well, BTW, is there any plan for such “re-engineering”?
No, there are no plans, as the current approach covers the vast majority of use cases. Spending significant engineering resources on something which will not get much use is not in the interest of the comunity.
participants (2)
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Chun Feng Wu -
Peter Krempa