| Posted | Nick | Remark | |
|---|---|---|---|
| #openstack-nova - 2018-10-03 | |||
| 19:32:22 | mriedem | i have also resorted to taking sleep aids to not wake up at 1am thinking about it... | |
| 19:34:35 | mriedem | i've found this helps https://www.youtube.com/watch?v=Lrle0x_DHBM | |
| 19:36:13 | melwitt | heh | |
| 19:43:15 | sean-k-mooney | mriedem: oh youtube look kind of weird to me when its rendering 4:3 aspect ratio videos | |
| 19:59:50 | mriedem | who here knows what actually happens to the guest when you stop/start a vmware/hyperv/xenapi/ironic/powervm VM? | |
| 20:00:03 | mriedem | specifically, the root disk of said VMs if it's volume-backed? | |
| 20:00:11 | mriedem | efried: does powervm in-tree support boot from volume yet? | |
| 20:00:30 | efried | edmondsw: ^ | |
| 20:00:35 | efried | looking... | |
| 20:05:00 | efried | mriedem: Does compute set destroy_disks=False to the destroy() method if booted from volume? | |
| 20:06:57 | efried | mriedem: I assume you're trying to find out whether the disk gets destroyed or not. | |
| 20:07:12 | efried | I can tell you this: In tree, we don't destroy volumes. | |
| 20:07:28 | efried | But I don't know whether we support bfv | |
| 20:07:38 | mriedem | efried: no not related to that | |
| 20:07:44 | mriedem | related to https://review.openstack.org/#/c/600628/ | |
| 20:07:51 | mriedem | which i haven't -1ed yet but it's coming | |
| 20:08:30 | mriedem | the virt driver doesn't destroy volumes, the compute manager orchestrates the detach and delete if bdm.terminate_on_deletion is True | |
| 20:08:50 | mriedem | i'm mostly wondering if the virt driver will disconnect and reconnect volumes on simple stop/start operatoins | |
| 20:08:57 | mriedem | for libvirt, we do - starting around queens or rocky | |
| 20:10:05 | efried | We don't disconnect anything on power-off | |
| 20:10:53 | efried | That said, I'm not 100% sure the *platform* retains ownership of that resource in such a way that you couldn't attach it to something else while the instance is powered off. | |
| 20:11:17 | efried | Gerald would be better equipped to answer this stuff. But he ain't here. | |
| 20:16:33 | edmondsw | mriedem re: bfv for powervm in-tree... I believe the code is close enough that it might work, but it's untested and there is at least one improvement we should make | |
| 20:18:05 | edmondsw | mriedem why would you disconnect and reconnect volumes on stop/start? | |
| 20:20:52 | sean-k-mooney | edmondsw: the libvirt driver destorys the domain and recreates it on start stop | |
| 20:21:06 | edmondsw | right... why? | |
| 20:21:18 | sean-k-mooney | edmondsw: so its proably done as a sideffect of that | |
| 20:21:20 | mriedem | comments inline in that spec | |
| 20:22:29 | sean-k-mooney | edmondsw: legacy reasons but we treat stop like delete as far as libvirt is concerend but we dont delete the disk obviously | |
| 20:23:29 | sean-k-mooney | we do detach all ports, gpus ectra when we shut down the vm but we still retain owner ship of them in placement/the resouce tracker | |
| 20:24:58 | edmondsw | ok. I'll assume "legacy reasons" means there's no reason for other drivers to consider doing that | |
| 20:26:11 | sean-k-mooney | well there is one but its not a good one. if you are using iscsi volumes by detaching the volume on stop it reduces memory uses on the issci server | |
| 20:27:00 | sean-k-mooney | which if its hardware based also means we can potenailly free up other hardware resouces but that also means the vm can fail to start back up if somting else grabs the last slot | |
| 20:27:31 | sean-k-mooney | that said you would have max out your cloud stroage at that point so you have bigger issue then one vm not starting | |
| 20:28:14 | sean-k-mooney | edmondsw: i dont know if there is a actul usecase where you would want to disconnect today but mayber there is | |
| 20:28:31 | edmondsw | sean-k-mooney tx for the explanation | |
| 20:30:34 | sean-k-mooney | i know some people want to be able to do things with bfv root volumes when the instace is offline too but i kindof zoned out at the ptg for that conversation. | |
| 20:30:48 | mriedem | sean-k-mooney: that is exactly the spec i'm referring to above | |
| 20:30:52 | mriedem | and why i'm asking about this | |
| 20:31:05 | sean-k-mooney | mriedem: ah ok that make more sense. | |
| 20:31:10 | mriedem | because i'm pretty sure swapping the root volume while the instance is stopped was not part of the originally approved spec | |
| 20:31:15 | mriedem | and s10 got Kevin_Zheng to change it | |
| 20:31:22 | mriedem | b/c of how the libvirt driver works | |
| 20:31:31 | mriedem | and i'm asserting that's not a good enough reason... | |
| 20:32:07 | sean-k-mooney | right i think haveing an expcit api to say detach volume for stoped instacnce would be better | |
| 20:32:31 | sean-k-mooney | e.g. not assumeing its implcitly detatched when you stop | |
| 20:32:33 | mriedem | well, the virt driver could just refuse to detach the root volume while the instance is stopped | |
| 20:32:46 | mriedem | if it doens't support it and raise an exception which gets recorded as a fault | |
| 20:32:58 | sean-k-mooney | mriedem: it could but did they not want to allow that? | |
| 20:33:18 | sean-k-mooney | e.g. detaching root volume when its stoped. that would be almost a noop for libvirt | |
| 20:33:23 | mriedem | the spec is proposing that you can swap the root volume while the instance is offloaded or stopped | |
| 20:34:16 | sean-k-mooney | right but you could do that by createing a new volume. stoping the instance. detach the root volmu and attach the volume created in step 1 then start | |
| 20:34:43 | sean-k-mooney | do you need an explcit api to do the swap as an atopmic operation | |
| 20:34:55 | mriedem | no, and that is what the spec is proposing | |
| 20:35:01 | mriedem | "createing a new volume. stoping the instance. detach the root volmu and attach the volume created in step 1 then start" | |
| 20:35:22 | mriedem | my point is, i don't know that all virt drivers could handle that today for the root volume | |
| 20:35:26 | mriedem | while the instance is stopped | |
| 20:35:45 | sean-k-mooney | ha ok am perhaps | |
| 20:36:23 | sean-k-mooney | i cant think why they could not if they support rebuild | |
| 20:36:49 | sean-k-mooney | its basicaly the same thing except we are not chaning host | |
| 20:37:45 | mriedem | rebuild does a driver.destroy and then a driver.spawn | |
| 20:37:51 | mriedem | it assumes destruction | |
| 20:38:01 | mriedem | i can't say that stop/start assume that same thing | |
| 20:38:27 | mriedem | same with shelve/unshelve | |
| 20:38:37 | mriedem | shelve does a driver.destroy and unshelve does a driver.spawn | |
| 20:39:08 | mriedem | sean-k-mooney: haven't you been working for like 20 straight hours at this point or something? | |
| 20:39:17 | mriedem | at what point do you become drunk by exhaustion? | |
| 20:39:46 | sean-k-mooney | mriedem: all of this is true. i would be surprised if this could not be supported on multiple hyperviors but its good to check. | |
| 20:40:14 | sean-k-mooney | haha not quite but if i get tired enough i do find it harder to concentrate. | |
| 20:41:00 | sean-k-mooney | i have been working sine 10:30 + i took an hour for lunch but ya im just finishing up for the day | |
| 20:41:27 | mriedem | pretty sure you said you were finishing for the day about 4 hours ago | |
| 20:41:56 | sean-k-mooney | i did finish rather late last night. ya got distracted with a few things | |
| 20:44:24 | sean-k-mooney | i really need to file my ptg expensice tomrrow... i started twice today but then got pull into email threads + code. | |
| 20:44:56 | sean-k-mooney | thats what i was trying to figure out for the last 30 mins but it can wait | |
| 20:45:11 | sean-k-mooney | talk to you tommorw | |
| 20:46:46 | melwitt | mriedem, tssurya: I told dansmith we're skipping the meeting based on the earlier convo | |
| 20:47:07 | tssurya | melwitt: ack, thanks for the info :) | |
| 20:47:09 | melwitt | he's not going to be back in time anyway | |
| 20:47:42 | mriedem | he said he would be back in time | |
| 20:47:45 | tssurya | wfm, Its too late here anyways, you guys have a good day | |
| 20:47:59 | mriedem | <3 broken | |
| 20:48:06 | melwitt | heh | |
| 20:48:19 | tssurya | :) | |
| 20:49:38 | mriedem | https://bugs.launchpad.net/nova/+bug/1795966 | |
| 20:49:38 | openstack | Launchpad bug 1795966 in OpenStack Compute (nova) "<class 'oslo_db.exception.DBNonExistentTable'> (HTTP 500)" [Undecided,Invalid] | |
| 20:50:15 | melwitt | meanwhile, gd consoleauth. we have an API where you can 'show' your console auth token. and that is making the deprecation nightmare worse. have to figure out if/how to adjust this for the database backend | |
| 20:50:51 | melwitt | mriedem: that must be the shortest bug report ever | |
| 20:50:56 | mriedem | https://developer.openstack.org/api-ref/compute/#create-remote-console ? | |
| 20:51:11 | melwitt | https://developer.openstack.org/api-ref/compute/#show-console-connection-information | |
| 20:51:31 | mriedem | ah heh | |
| 20:51:36 | melwitt | FML | |
| 20:51:56 | mriedem | well, | |
| 20:52:18 | mriedem | oh heh you can't know which cell to route it to right | |
| 20:52:23 | mriedem | b/c the token isn't mapped in the api | |
| 20:52:36 | mriedem | you'll have to iterate the cell dbs looking for that token id | |
| 20:53:05 | melwitt | no... which I'm trying to remember, what did I find last time I looked at this. arrrrgghh | |
| 20:55:03 | mriedem | hmm, we only store the hashed token in the db right | |
| 20:55:14 | mriedem | and that's not what the API would have in it? | |
| 20:55:47 | melwitt | yeah only the hashed token. and I think the API takes the unhashed token from the user | |
| 20:56:22 | mriedem | ha, cool | |