| Posted | Nick | Remark | |
|---|---|---|---|
| #openstack-nova - 2025-03-24 | |||
| 15:57:20 | gibi | more | |
| 15:57:43 | sean-k-mooney | right and that does https://github.com/openstack/placement/blob/master/placement/tests/functional/gabbits/allocations-post.yaml#L212-L236 | |
| 15:58:27 | dansmith | gibi: yeah it's not just allocation, it's allocation with the capacity check | |
| 15:58:35 | dansmith | *failing | |
| 15:59:16 | gibi | this also has some coverage https://github.com/openstack/placement/blob/master/placement/tests/functional/db/test_allocation.py but I'm not against adding more :) | |
| 16:04:17 | dansmith | that's really the only place in python, but yeah | |
| 16:07:05 | gibi | in cases when I'm not sure what is covered and not covered I tend to go in and break the code in certain cases to see if it caught be tests. Maybe there are test cases in wrongly named test files hiding | |
| 16:27:03 | sean-k-mooney | gibi: i dont think placement has the saem level fo in depth testing that nova has in genral. gabit is greate but often it was used instead of unit and functional testin instead of in addtion to them | |
| 16:27:57 | sean-k-mooney | one of the test case that i looked at was teh sole testing in the commit that added a new microverions | |
| 16:28:11 | sean-k-mooney | there may have been other changes in teh serise | |
| 16:28:39 | sean-k-mooney | but if that really was the only commit to implemnt the microversion it shows that gabbit testing was considered enough coverage for an api change | |
| 16:37:35 | dansmith | gibi: yeah I was going to create a reproducer for the issue and then break it to make sure it starts working.. so I guess we'll see if something stops when I do :) | |
| 16:44:27 | simondodsley | hi - i'm looking for advice on how to disable `discard` on a single cinder volume that is coming from a cinder driver where `discard` is hardcoded to be `True`. A customer is having issues with multiattach volumes that they want to use for Windows clustering, in that the SCSI page 83h doesn't appear to be passing through the SCSI reservation settings. | |
| 16:45:29 | simondodsley | I read that `nodiscard` may resolve this, but can't work out how to do the override. Overriding the whole backend for a test would be an option, but as I say the cinder driver has `disacrd` hardcoded. Is there somethin in nova that can help? | |
| 16:46:40 | sean-k-mooney | simondodsley: so windwos clustering required the vm to be create with a volume configured to use type=lun which cant be set durign attach only vm creation | |
| 16:46:47 | dansmith | yep, was just going to say ^ | |
| 16:47:01 | sean-k-mooney | we shoudl probaly fix that at some point | |
| 16:47:13 | sean-k-mooney | but anyway i am not sure if you can overried that with our libvirt section | |
| 16:47:17 | dansmith | is that enough to enable it? I thought not | |
| 16:47:25 | sean-k-mooney | we have a cofnig option for discard but i tought it was for nova provisioend storage | |
| 16:47:27 | dansmith | I thought lun was the only way | |
| 16:47:43 | sean-k-mooney | no i think you need lun for scsi v3 | |
| 16:47:49 | simondodsley | so how do we set the type=lun at vm creation? | |
| 16:47:57 | sean-k-mooney | i just ment that even behond that im not sure if you can overried discard form nova | |
| 16:49:03 | sean-k-mooney | simondodsley: so the only discard cofnig im awre of in nova is https://docs.openstack.org/nova/latest/configuration/config.html#libvirt.hw_disk_discard which woudl turn it off for the host but that says "nova managed disks" | |
| 16:49:18 | dansmith | sean-k-mooney: I think if they want the guest to use discard and have that make it all the way to the actual physical device they need to use lun, no? | |
| 16:49:47 | sean-k-mooney | dansmith: well that what will happen if discard is enabeld on the cinder volume in the connection info | |
| 16:49:54 | dansmith | I thought libvirt discard would only hit the qemu storage driver, like ceph or qcow2 | |
| 16:50:19 | sean-k-mooney | dansmith: i guess there are two diffent things happenign here | |
| 16:50:51 | sean-k-mooney | simondodsley made the assertion that truning of discard migh help with the scsi command making it to the backend. i think we both agree it not related to that | |
| 16:51:05 | dansmith | tight | |
| 16:51:11 | dansmith | *right :) | |
| 16:51:25 | sean-k-mooney | simondodsley: so if you look at the server create api https://docs.openstack.org/api-ref/compute/#create-server | |
| 16:52:10 | sean-k-mooney | there is an option device_type filed in the request | |
| 16:52:17 | sean-k-mooney | in the block device mappings | |
| 16:52:50 | sean-k-mooney | sorry that might not be the correct filed | |
| 16:53:03 | sean-k-mooney | i think you want block_device_mapping_v2.disk_bus i will neeed to check the other doc | |
| 16:53:25 | sean-k-mooney | https://docs.openstack.org/nova/latest/user/block-device-mapping.html | |
| 16:53:40 | sean-k-mooney | ok no so you want disk_bus=scsi and deivce_type=lun | |
| 16:54:02 | sean-k-mooney | """disk_bus and device_type - low level details that some hypervisors (currently only libvirt) may support. Some example disk_bus values can be: ide, usb, virtio, scsi, while device_type may be disk, cdrom, floppy, lun. This is not an exhaustive list as it depends on the virtualization driver, and may change as more support is added. Leaving these empty is the most common | |
| 16:54:04 | sean-k-mooney | thing to do.""" | |
| 16:54:48 | simondodsley | ok - so how would that be forced from the comand line, or the gui? | |
| 16:55:01 | sean-k-mooney | you cant do it form horizon | |
| 16:55:12 | sean-k-mooney | from the cli you an do it when creating the block device mapppings | |
| 16:55:32 | sean-k-mooney | https://docs.openstack.org/python-openstackclient/latest/cli/command-objects/server.html#server-create | |
| 16:55:54 | sean-k-mooney | you have to use teh --block-device parmater instead of --volume | |
| 16:55:59 | simondodsley | awesome - i see - thank you. We will give that a try | |
| 16:55:59 | sean-k-mooney | https://docs.openstack.org/python-openstackclient/latest/cli/command-objects/server.html#cmdoption-openstack-server-create-block-device | |
| 16:57:46 | sean-k-mooney | simondodsley: when dan fixed this he added some tempest test that validate this is functional with lvm and multi attache. although obviosly not with a windows workload | |
| 16:58:02 | sean-k-mooney | simondodsley: but we do have coverage of creating a vme with a mutiatch volume in lun mode | |
| 16:58:42 | sean-k-mooney | https://github.com/openstack/tempest/blob/f4a8698b97a5433b8e64df408aace2fb14c2cb22/tempest/api/compute/volumes/test_attach_volume.py#L469 | |
| 16:58:45 | simondodsley | and this will ensure that SCSI page 83 will be passed through correctly? | |
| 16:59:21 | sean-k-mooney | do you ahve a refence to that defintiion. it will ensure that scsiv3 command are aviable to the guest | |
| 16:59:29 | sean-k-mooney | without that you onlyhave access to v2 commands | |
| 17:02:37 | sean-k-mooney | simondodsley: by the way we only fixed this fucntionaly in recent version of nova | |
| 17:02:47 | sean-k-mooney | i think form dalmation on | |
| 17:03:02 | simondodsley | oh - so it won't work on caracal | |
| 17:03:34 | simondodsley | how did anyone every use windows clustering before this fix then? | |
| 17:03:37 | sean-k-mooney | i can check when we fixed it but no livbirt changed it api because qemu stop supproting the serial atibute with type lun a few years ago | |
| 17:03:58 | sean-k-mooney | windows supprot clustierning with other ways of doing synconisation | |
| 17:04:12 | sean-k-mooney | i.e. not file system absed it has 3-4 modes | |
| 17:04:27 | sean-k-mooney | so either they used one of the other mode or they didnt do it with libvirt | |
| 17:04:51 | sean-k-mooney | i.e. they were usihg hyperv or vmware or ironic | |
| 17:04:52 | simondodsley | this is the error from windows - `Physical disk {} does not have the inquiry data (SCSI page 83h VPD descriptor) that is required by failover clustering. Status: The request is not supported` | |
| 17:05:09 | sean-k-mooney | yep | |
| 17:05:18 | dansmith | that's what lun should fix | |
| 17:05:32 | simondodsley | but it only from dalmation... | |
| 17:05:47 | sean-k-mooney | or really old libvirt | |
| 17:05:52 | dansmith | simondodsley: also, clustered windows is not cloudy and openstack really focuses on cloudy workloads :) | |
| 17:06:08 | simondodsley | i know that, but tell customers :D | |
| 17:06:08 | dansmith | so that's why it's recent | |
| 17:06:12 | dansmith | just saying. | |
| 17:06:55 | sean-k-mooney | so the fix in dalmation was https://github.com/openstack/nova/commit/575ff86a4f1572786d66639f774405fbc074fdb1 | |
| 17:07:07 | sean-k-mooney | which depend on another change that was done in caracal | |
| 17:07:28 | sean-k-mooney | it might be possibel to backport to caracal but not before | |
| 17:07:43 | sean-k-mooney | the prior change i dont think is backportable (using alias) | |
| 17:08:04 | dansmith | not backportable upstream, but doable for simondodsley you mean | |
| 17:08:49 | sean-k-mooney | well if it just needs https://github.com/openstack/nova/commit/575ff86a4f1572786d66639f774405fbc074fdb1 that might be ok upstream but the prior change to use the alias instead of serial to lookup the devices is much more invasive | |
| 17:08:54 | sean-k-mooney | but that already in caracal | |
| 17:09:35 | simondodsley | if we can backport the patch to caracal I can try and convince canonical to apply it downstream as well | |
| 17:10:49 | sean-k-mooney | simondodsley: its a serise of 3 patches https://review.opendev.org/q/topic:%22lun-device-serial%22 | |
| 17:11:03 | sean-k-mooney | simondodsley: i would like to get elodilles input on if that is upstream backporable | |
| 17:18:15 | sean-k-mooney | simondodsley: strictly speaking https://bugs.launchpad.net/nova/+bug/2065084 was a latent bug for years so i think it could be backported upstram but it does not hurt to ask | |
| 17:19:03 | sean-k-mooney | the new feature that was added in caracal that it implcictly depend on is not backportable upstream really | |
| 17:19:26 | simondodsley | just so i haven't got this wrong... from Dalmation we can use `openstack server create --block-device disk_bus=scsi,disk_type=lun,volume_size=x,volume_type=whatever` | |
| 17:19:27 | sean-k-mooney | so if it was backproted it would only be to 2024.1 | |
| 17:19:38 | simondodsley | i thin that backpor would be fine | |
| 17:19:59 | sean-k-mooney | yes taht looks correct to me | |
| 17:20:03 | simondodsley | cool | |
| 17:20:12 | sean-k-mooney | well you might need to set the destination type | |
| 17:20:32 | sean-k-mooney | destination_type=volume | |
| 17:20:55 | sean-k-mooney | you also need to set the source type | |
| 17:21:12 | sean-k-mooney | basically need to set all the filed for the block device mappings for that entry | |
| 17:22:03 | dansmith | sean-k-mooney: what's the justification for backport upstream? it's been broken forever, not sure it ever worked, not a regression in recent memory and thus seems entirely a feature to me | |
| 17:22:52 | sean-k-mooney | dansmith: just that it was tracked as a bug upstream as it worked in theory with old libvirt | |
| 17:23:02 | sean-k-mooney | but i agree that its not a very strong justification | |
| 17:23:23 | sean-k-mooney | that why im relucatnt to propose ti without impot form the stable team | |
| 17:23:35 | sean-k-mooney | e.g. elodilles or others | |
| 17:24:18 | dansmith | okay I thought you were implying it had a good justification.. to me it's just a feature.. if it ever worked it was long enough ago that it's not really a regression, | |
| 17:24:36 | dansmith | so even if it's fixing a bug that never worked, it's enabling a whole new workflow, behaviors, etc.. very feature-y to me | |