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#openstack-nova - 2022-09-22
15:18:58 gmann bauzas: yes. only for Antelope
15:19:13 bauzas yeah, just verified https://governance.openstack.org/tc/reference/runtimes/zed.html
15:19:19 bauzas 20.04
15:19:22 bauzas we're all good
16:00:20 melwitt sean-k-mooney: I wanted to get your thoughts on this bug fix, do you think this is an ok thing to do or any problems with it? I was unsure about whether it's proper to use qemu-img info to determine the disk format of a volume https://review.opendev.org/c/openstack/nova/+/858836
16:02:03 sean-k-mooney is this related ot luks
16:02:27 melwitt sean-k-mooney: no, it's just nfs
16:02:28 sean-k-mooney oh no its differnt
16:02:45 sean-k-mooney ya i tough i swa an nfs related patch for something like this
16:02:52 sean-k-mooney oh i rememebr the bug
16:03:08 sean-k-mooney so snapshots on nfs have to be qcow right
16:03:23 melwitt right
16:03:33 sean-k-mooney like the os-assisted-snapshost api say it must be that
16:03:36 sean-k-mooney ok
16:03:42 melwitt yes it does
16:04:11 sean-k-mooney so when i was looking at the snapshot code i think i say we shoudl usjt update it to be qcow
16:04:19 melwitt but on our side we store the volume attachment connection_info and the format captured there represents the format of the volume (which is raw) not the snapshot (which is qcow2)
16:04:58 sean-k-mooney ya
16:05:03 melwitt yeah, the thing is how to "remember" that when the instance is rebooted for example
16:05:50 sean-k-mooney let me see if i can find the code i was suggesting changing but basicaly i was suggestin updating the format on the image
16:06:07 sean-k-mooney what your dowing sound valid
16:06:13 sean-k-mooney just not sure if its requried
16:06:18 melwitt oh, hm
16:07:54 sean-k-mooney https://github.com/openstack/nova/blob/master/nova/virt/libvirt/driver.py#L2932-L2958
16:08:00 sean-k-mooney i tought we could fix that in that code
16:09:04 melwitt ok, I will look at that. thanks for the pointer
16:10:16 sean-k-mooney honestly i think when we create teh snapshot the connection info should get updated to qcow
16:11:11 melwitt sean-k-mooney: I tried that first https://review.opendev.org/c/openstack/cinder/+/857528 and it's run into problems
16:11:32 melwitt if you have any thoughts on that one as well
16:12:06 sean-k-mooney well the backend driver should be reprotign it as qcow no?
16:12:14 melwitt because unless the connection_info gets updated in cinder, we will overwrite it when we do refresh connection_info
16:12:23 sean-k-mooney like its a bug for them to be returnign raw after the snapshot is created
16:12:33 melwitt cinder only keeps the volume format, not the snapshot format
16:12:46 melwitt that's the only thing it knows how to return
16:13:10 sean-k-mooney right so the volume format should be updated once we snapshot right
16:13:19 sean-k-mooney because it has now changed
16:13:30 melwitt yeah, so I tried that and it broke volume extend
16:13:35 sean-k-mooney fun
16:13:53 melwitt because the resize needs to change the size of the raw backing file iiuc
16:14:05 sean-k-mooney so we could work around this in nova but i think we shoudl also bring this up with cinder in the ptg
16:14:13 melwitt so if we stored qcow2, that blows up when it tries to resize raw by specifying qcow2
16:14:22 sean-k-mooney well extend is not supported with nfs
16:14:28 sean-k-mooney so that shoudl not be a problem
16:14:29 melwitt it is
16:14:31 sean-k-mooney its not
16:14:42 sean-k-mooney we have a spec and open bug for it
16:14:46 melwitt it's in the nfs job, that's how I know it failed :P
16:14:56 sean-k-mooney well its not supported
16:15:06 melwitt ?
16:15:11 sean-k-mooney https://bugs.launchpad.net/cinder/+bug/1870367
16:15:52 sean-k-mooney https://review.opendev.org/c/openstack/nova-specs/+/855490
16:16:03 sean-k-mooney that is the spec to add extend support in A
16:16:54 melwitt huh.
16:17:03 melwitt I wonder what/how it's running the tests on nfs and passing currently
16:17:23 sean-k-mooney it can work but i think its racy
16:17:31 melwitt ugh, ok.
16:17:35 sean-k-mooney basicaly they tought they fixed it
16:17:46 sean-k-mooney but the external event is async
16:17:56 sean-k-mooney so there is no way for cidner ot know if it works or not
16:18:25 sean-k-mooney there is also https://bugs.launchpad.net/cinder/+bug/1978294
16:19:51 melwitt yeah.. I have seen that but I didn't remember it when I saw the extend test fail
16:21:03 melwitt I'll add something to the ptg agenda about this
16:22:06 melwitt bc even if we skipped the extend tests for nfs, changing the actual volume format in the metadata to qcow2 afaik isn't correct because it's the snapshot that is qcow2 and the volume itself is still raw. so we're still stuck
16:33:09 stephenfin melwitt: Random question. It appears the '<class>' argument to 'nova quota-class-show <class>' doesn't do anything. Is that expected?
16:34:14 sean-k-mooney melwitt: see the way this works with nfs that is not reallly true
16:34:22 melwitt stephenfin: I don't think that's expected. are you running like 'nova quota-class-show default'?
16:34:52 sean-k-mooney when we create the snapshot the snapshot point to the orginal file and the vm is now runnign form the qcow that is created on top right
16:35:02 gibi gmann, stephenfin: sorry I focused elsewhere. I see stephenfin approved it now
16:35:02 melwitt stephenfin: bc default is the only quota class that automatically exists, any others have to be created by the admin user
16:35:16 melwitt sean-k-mooney: yes right
16:35:17 sean-k-mooney so the snapshot is actully raw and the volume is now qcow?
16:35:52 stephenfin https://paste.opendev.org/show/bUrfKrK6aKCSbqfRJzNZ/
16:35:54 sean-k-mooney so its the revers of what i sugeste orginally the snapshot remaisn the same but the volume format changes
16:35:55 stephenfin melwitt: ^
16:37:05 sean-k-mooney stephenfin: why are you using 2.1
16:37:21 stephenfin to make sure we hadn't broken things in a newer microversion
16:37:23 melwitt stephenfin: ok, I _think_ what that's doing is if you pass a class that doesn't exist, it will show you the default (which is not super helpful, but is accurately showing what would be used if you tried to use a nonexistent quota class)
16:37:57 stephenfin what would a real class be?
16:37:59 melwitt stephenfin: if you create a new class and put different values in it and then show it I think (hopefully) it would show you that new class values
16:38:43 melwitt stephenfin: only default out of the box but you can create quota classes, that's the only way you can get other quota classes
16:39:38 stephenfin Ah, apparently *only* 'default' is supported https://docs.openstack.org/nova/latest/admin/quotas.html
16:39:51 stephenfin Note
16:39:51 stephenfin Only the default class is supported by nova.
16:41:05 melwitt yeah, at some point in the past we decided that bc quota classes was a rax specific thing they were doing with an external service/system that they had
16:41:19 melwitt and as far as we knew no one else ever used it
16:41:32 stephenfin Nope, tell a lie. Apparently I wrote the quota docs
16:41:37 stephenfin Jaysus
16:41:39 melwitt :)
16:42:08 stephenfin Okay, so that argument means diddly squat in practice
16:42:29 melwitt so, you're right we don't support it but if you were curious how the command could work, that's how I remember it working
16:43:12 stephenfin Right. I must check if any of this is relevant for neutron or cinder. If not, I might get the interns to deprecate all the class-based stuff in OSC. It's just confusing
16:43:40 stephenfin melwitt++ thanks :)
16:44:09 melwitt stephenfin: yeah, I think it's pretty safe to do that. technically someone could change the default quota class values and nova would use that if it's in the right order of precedence ... but I don't think that really helps anyone
16:44:36 melwitt just increases confusion
16:45:24 stephenfin i.e. using 'quota-class-update'?
16:45:36 melwitt yes
16:46:28 stephenfin Okay. I suspect re-implementing that as e.g. 'openstack quota set --default --instances $INSTANCES' or 'openstack default quota set --instances $INSTANCES' would make more sense
16:46:46 stephenfin and deprecate (for removal) all references to quota classes
16:47:11 stephenfin Sound reasonable?
16:47:49 melwitt yeah, I think that makes sense. quota classes is how you can change defaults over the API (as opposed to the config options). so maybe people do do that (?)

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