| Posted | Nick | Remark | |
|---|---|---|---|
| #openstack-nova - 2021-03-09 | |||
| 13:14:44 | sean-k-mooney | lyarwood: we dont really suppor t mixing buses properly | |
| 13:14:59 | sean-k-mooney | i dont think we generate the contoler properly in all cases | |
| 13:15:41 | lyarwood | sean-k-mooney: the instance was already using SCSI in the bus=scsi case so that should work | |
| 13:16:00 | lyarwood | sean-k-mooney: and bus=usb worked for me while I was testing this back in the day with virtio disks attached | |
| 13:16:21 | sean-k-mooney | yep but i thik we have some edge cases with scsi and virtio blk | |
| 13:16:50 | lyarwood | yeah | |
| 13:17:05 | sean-k-mooney | usb would likely have worked because the usb contoler was previously always added by libvirt | |
| 13:17:25 | sean-k-mooney | i have seen issue where the scsi contoler was not alwasy added but that might have been fixed by now | |
| 13:17:33 | lyarwood | jrosser: just building an env now to play with this | |
| 13:18:19 | jrosser | lyarwood: oh cool, thankyou :) | |
| 13:18:31 | lyarwood | jrosser: oh wait, does this reproduce if you use a different image? | |
| 13:18:49 | jrosser | i can try that | |
| 13:19:18 | lyarwood | yeah please, it might be the rescue disk is finding the original disk first and mounting it as the root filesystem as the labels match | |
| 13:19:49 | lyarwood | so we are booted into the kernel from the rescue disk using the filesystem from the original | |
| 13:20:38 | jrosser | also somewhat contrary to the stuff right at the end of here, leaving --image off does some fail-y thing i've not yet found https://docs.openstack.org/nova/latest/user/rescue.html | |
| 13:22:07 | lyarwood | hmm with a boot from volume instance it should try to boot from the original image referenced by the volume, if one is present. I forget what the behaviour is if an image wasn't used to create the volume. | |
| 13:24:46 | jrosser | from the wording i'd inferred that no --image would make it use the 'default', i.e the one from the instance being rescued | |
| 13:28:00 | sean-k-mooney | do we support rescue for BFV | |
| 13:28:05 | sean-k-mooney | we didnt for a long time | |
| 13:28:28 | sean-k-mooney | i think it was added in the last 2-3 cycle but cant recall if it landed | |
| 13:28:41 | jrosser | ussuri i think | |
| 13:29:00 | sean-k-mooney | ya i know we still have no supprot for rebuild with bfv | |
| 13:30:11 | jrosser | ah thats interesting, changing the rescue image to one != the original instance makes things work a whole lot better | |
| 13:30:32 | sean-k-mooney | jrosser: the image for rescue if you dont pass an image is the image use to boot the vm unless a rescue image is set in the nova.conf https://docs.openstack.org/nova/latest/configuration/config.html#libvirt.rescue_image_id | |
| 13:30:37 | jrosser | i rescued a focal vm with bionic image and thats now as i expect | |
| 13:30:39 | sean-k-mooney | jrosser: yep it normally does | |
| 13:31:15 | sean-k-mooney | it should work in both casees but you often dont have the same disk lable issues | |
| 13:31:35 | jrosser | theres a bunch of trap doors for the unwary here :) | |
| 13:32:11 | sean-k-mooney | for what its worth i have generally not had issues with this. its typeically just worked | |
| 13:32:23 | sean-k-mooney | even before the stable rescuse work | |
| 13:35:43 | jrosser | heres what i get if i don't pass --image http://paste.openstack.org/show/803379/ | |
| 13:36:24 | lyarwood | jrosser: kk that's a bug | |
| 13:36:34 | lyarwood | jrosser: but glad the original issue is resolved at least | |
| 13:38:50 | lyarwood | https://github.com/openstack/nova/blob/31889ce296d1e1a62fe5825292479009118ddfab/nova/compute/manager.py#L4123-L4130 doesn't look right | |
| 13:38:52 | jrosser | lyarwood: would you expect hw_rescue_bus=scsi to work? | |
| 13:39:17 | lyarwood | jrosser: with a different image and an instance that already had a disk attached via SCSI yes | |
| 13:39:51 | jrosser | feels like something else there as i get "No Bootable device" in the instance console | |
| 13:44:00 | lyarwood | jrosser: would you mind raising a bug for that and the API error above when --image is missing? | |
| 13:44:17 | lyarwood | I'm not sure about the SCSI failure to find a boot device tbh | |
| 13:44:32 | lyarwood | unless again it's something weird with the image | |
| 13:44:47 | sean-k-mooney | jrosser: which image did you set the rescue bus on? | |
| 13:45:02 | jrosser | the one i'm specifying with --image | |
| 13:45:05 | sean-k-mooney | if you dont specify it it would have to be on the original image | |
| 13:45:20 | sean-k-mooney | ya ok that should be the image whos metadata we use | |
| 13:46:55 | jrosser | in this case turns out those options are set on both images i've tried as the rescue image now | |
| 13:47:12 | jrosser | one of which is the original instance image | |
| 14:13:52 | jrosser | lyarwood: bug reports done | |
| 14:14:42 | jrosser | thankyou again for your help, i have something usable now with the usb bus and understanding the need for a different rescue image | |
| 14:17:00 | lyarwood | jrosser: np and thanks for the bugs, I'll try to get them resolved after feature freeze later this week | |
| 14:36:40 | sean-k-mooney | lyarwood: by the way do you know why the volumn detach is sometime failing in the live migration job | |
| 14:40:05 | sean-k-mooney | looks like its hitting nova.exception.DeviceDetachFailed: Device detach failed for vdb: Unable to detach the device from the live config. | |
| 14:41:53 | lyarwood | sean-k-mooney: no, I've been trying to push gibi's rework along to see if that resolved it tbh | |
| 14:42:24 | sean-k-mooney | http://logstash.openstack.org/#dashboard/file/logstash.json?query=message%3A%5C%22Unable%20to%20detach%20the%20device%20from%20the%20live%20config%5C%22%20AND%20loglevel%3A%20ERROR | |
| 14:43:00 | lyarwood | sean-k-mooney: there's nothing obvious in the logs but I wonder if it could be related to https://bugs.launchpad.net/cinder/+bug/1917750 | |
| 14:43:01 | openstack | Launchpad bug 1917750 in Cinder "Running parallel iSCSI/LVM c-vol backends is causing random failures in CI" [Undecided,New] | |
| 14:43:07 | sean-k-mooney | ~300 hits in 30 days | |
| 14:43:52 | sean-k-mooney | im seeing some libvirt issue on the contoler too not the node with teh detach issue | |
| 14:44:47 | lyarwood | do you have an example to hand? | |
| 14:45:19 | sean-k-mooney | am its hitting my vdpa pataches but also neutron let me get one | |
| 14:47:54 | sean-k-mooney | so ya https://review.opendev.org/c/openstack/nova/+/778350/4 https://zuul.opendev.org/t/openstack/build/fb643b53835341ac8589afeadfa7044d/logs | |
| 14:49:08 | sean-k-mooney | its showing up in neutron too https://review.opendev.org/c/openstack/neutron/+/777785 | |
| 14:49:50 | sean-k-mooney | in https://zuul.opendev.org/t/openstack/build/32f3dd64008b469eb9fb8b13ed33f137 | |
| 14:50:04 | sean-k-mooney | so i think this is just an issue with master in general | |
| 14:50:27 | sean-k-mooney | it could be related to https://bugs.launchpad.net/cinder/+bug/1917750 maybe havent looked at it yet | |
| 14:50:28 | openstack | Launchpad bug 1917750 in Cinder "Running parallel iSCSI/LVM c-vol backends is causing random failures in CI" [Undecided,New] | |
| 14:57:49 | lyarwood | sean-k-mooney: yeah I think it's related | |
| 15:01:19 | lyarwood | gah | |
| 15:01:23 | lyarwood | yeah it's that | |
| 15:02:15 | lyarwood | so we end up in a situation where one test attaches a volume to the host as /dev/sda from c-vol LVM/iSCSI backend #1 | |
| 15:02:39 | lyarwood | another test then attaches another volume with the same WWN to the hsot as /dev/sdb from c-vol LVM/iSCSI backend #2 | |
| 15:03:07 | lyarwood | the first test finishes and removes what it thinks is the first volume attachment | |
| 15:03:13 | lyarwood | but it's actually the second | |
| 15:03:36 | lyarwood | leaving libvirt unable to detach the device from the instance as I assume it can't flush | |
| 15:04:02 | lyarwood | I guess our current code swallows or ignores the failure from the libvirt and just retries? | |
| 15:04:27 | sean-k-mooney | porbaly ya | |
| 15:04:34 | sean-k-mooney | we dont use the events yet | |
| 15:04:51 | sean-k-mooney | so we need to revert running those n parrallel | |
| 15:05:11 | sean-k-mooney | although is this not a os-brick bug | |
| 15:05:26 | sean-k-mooney | i mean the concurrent attach should work | |
| 15:05:29 | lyarwood | yeah it's a job topology bug | |
| 15:05:58 | lyarwood | it `works` but the first test will end up sending I/O to the volume from the second test | |
| 15:06:21 | lyarwood | something has changed recently somewhere in the stack to allow both backends to return the same WWN tbh | |
| 15:06:27 | bauzas | stephenfin: apologies for forgetting that a string is immutable | |
| 15:06:37 | lyarwood | unless people have always missed these failures | |
| 15:06:37 | sean-k-mooney | lyarwood: would not not be possible thouhg in general | |
| 15:06:52 | sean-k-mooney | for them to have the same WWN | |
| 15:07:56 | lyarwood | not with a real world backend | |
| 15:08:37 | lyarwood | https://en.wikipedia.org/wiki/World_Wide_Name | |
| 15:12:19 | sean-k-mooney | lyarwood: ya i tought if you have iscsi portals from different sotrage backend thw WWN was only uniq within any given portal | |
| 15:13:26 | sean-k-mooney | lyarwood: i dont think cinder is choosing the WWN for the volume | |
| 15:16:41 | lyarwood | right yeah that would make sense | |
| 15:22:29 | stephenfin | bauzas: nw. I've replied to the rest of your comments also | |
| 15:42:15 | bauzas | yeah I'll review again | |
| 15:42:36 | gibi | lyarwood: do I understand correclty from the scrollback that making some cinder test serial would help merging patches? | |
| 15:42:55 | lyarwood | gibi: removing c-vol from the computes would | |
| 15:43:33 | lyarwood | gibi: if we really need to run another c-vol service then it needs to be on the controller alongside the original | |
| 15:43:41 | lyarwood | gibi: just building an env now to prove things | |
| 15:43:43 | stephenfin | lyarwood, gibi, sean-k-mooney: any aversion to adding mypy to pre-commit? | |
| 15:43:59 | sean-k-mooney | not speciriclly no | |
| 15:44:00 | stephenfin | assuming I can do it while respecting mypy-files | |