Re: [openstack-dev] [nova] about live-resize down the instance
On 8/13/2018 4:42 PM, melanie witt wrote: From what I find in the PTG notes [1] and the spec, it looks like this didn't go forward for lack of general interest. We have a lot of work to review every cycle and we generally focus on functionality that impact operators the most and look for +1s on specs from operators who are interested in the features. From what I can tell from the comments/votes, there isn't much/any operator interest about live-resize. As has been mentioned, resize down is hypervisor-specific whether or not it's supported. For example, in the libvirt driver, resize down of ephemeral disk is not allowed at all and resize down of root disk is only allowed if the instance is boot-from-volume [2]. The xenapi driver disallows resize down of ephemeral disk [3], the vmware driver disallows resize down of root disk [4], the hyperv driver disallows resize down of root disk [5]. So, allowing only live-resize up would be a way to behave consistently across virt drivers. Somewhat related to this, but some feedback I got from our product teams this last week was they'd like to see the duplicate resource allocations during (cold) resize to same host fixed. Since Queens the migration record has the old flavor allocations and the instance holds the new flavor allocations, but the same-host compute node resource provider still has allocations from both during the resize, which might take it out of scheduling contention even though we only need to count the max() of any values between the old/new flavors. Our public cloud is very keen on maximizing efficient usage of hosts (packing) for cost reasons (obviously, and this is common) but this isn't just a public cloud cost savings thing. It's also an issue for, are you ready for this? **EDGE!!!** Simply because you could have one or two compute hosts at a site and can't afford the duplicate resource allocations in that case for a resize. Anyway, it's somewhat tangential to the live resize stuff, but it's an added complication in existing functionality that we should fix, and Kevin/Yikun/myself (one of us) plan on working on that in Stein. -- Thanks, Matt __ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Re: [openstack-dev] [nova] about live-resize down the instance
On Mon, 13 Aug 2018 09:46:41 -0600, Chris Friesen wrote: On 08/13/2018 02:07 AM, Rambo wrote: Hi,all I find it is important that live-resize the instance in production environment,especially live downsize the disk.And we have talked it many years.But I don't know why the bp[1] didn't approved.Can you tell me more about this ?Thank you very much. [1]https://review.openstack.org/#/c/141219/ It's been reviewed a number of times...I thought it was going to get approved for Rocky, but I think it didn't quite make it in...you'd have to ask the nova cores why not. It should be noted though that the above live-resize spec explicitly did not cover resizing smaller, only larger. From what I find in the PTG notes [1] and the spec, it looks like this didn't go forward for lack of general interest. We have a lot of work to review every cycle and we generally focus on functionality that impact operators the most and look for +1s on specs from operators who are interested in the features. From what I can tell from the comments/votes, there isn't much/any operator interest about live-resize. As has been mentioned, resize down is hypervisor-specific whether or not it's supported. For example, in the libvirt driver, resize down of ephemeral disk is not allowed at all and resize down of root disk is only allowed if the instance is boot-from-volume [2]. The xenapi driver disallows resize down of ephemeral disk [3], the vmware driver disallows resize down of root disk [4], the hyperv driver disallows resize down of root disk [5]. So, allowing only live-resize up would be a way to behave consistently across virt drivers. -melanie [1] https://etherpad.openstack.org/p/nova-ptg-rocky L690 [2] https://github.com/openstack/nova/blob/afe4512bf66c89a061b1a7ccd3e7ac8e3b1b284d/nova/virt/libvirt/driver.py#L8243-L8246 [3] https://github.com/openstack/nova/blob/afe4512bf66c89a061b1a7ccd3e7ac8e3b1b284d/nova/virt/xenapi/vmops.py#L1357-L1359 [4] https://github.com/openstack/nova/blob/afe4512bf66c89a061b1a7ccd3e7ac8e3b1b284d/nova/virt/vmwareapi/vmops.py#L1421-L1427 [5] https://github.com/openstack/nova/blob/afe4512bf66c89a061b1a7ccd3e7ac8e3b1b284d/nova/virt/hyperv/migrationops.py#L107-L114 __ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Re: [openstack-dev] [nova] about live-resize down the instance
On 08/13/2018 02:07 AM, Rambo wrote: Hi,all I find it is important that live-resize the instance in production environment,especially live downsize the disk.And we have talked it many years.But I don't know why the bp[1] didn't approved.Can you tell me more about this ?Thank you very much. [1]https://review.openstack.org/#/c/141219/ It's been reviewed a number of times...I thought it was going to get approved for Rocky, but I think it didn't quite make it in...you'd have to ask the nova cores why not. It should be noted though that the above live-resize spec explicitly did not cover resizing smaller, only larger. Chris __ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
[openstack-dev] [nova] about live-resize down the instance
Hi,all I find it is important that live-resize the instance in production environment,especially live downsize the disk.And we have talked it many years.But I don't know why the bp[1] didn't approved.Can you tell me more about this ?Thank you very much. [1]https://review.openstack.org/#/c/141219/ Best Regards Rambo__ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
