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#openstack-nova - 2019-11-08
15:58:57 lyarwood dansmith: eww okay so bcache also wouldn't work
15:59:10 dansmith lyarwood: yes, another "sell more hardware" feature for nova for sure:/
16:00:01 dansmith lyarwood: yeah, so I think the only way to do this reasonably is with CAS, which is crazy new and unproven, would require compiling kernel modules from source, etc
16:00:05 mriedem when is the last time zvm or powervm ci actually reported and worked? is it time for a warning log on startup of those drivers?
16:00:22 lyarwood dansmith: isn't dm-cache also an option here?
16:00:28 dansmith lyarwood: I love their FAQ page which says "Why do filesystem benchmark tools report that there is disk corruption? Oh don't worry about those silly errors!"
16:00:38 lyarwood L O L
16:00:39 dansmith lyarwood: not AFAIK, see my comments
16:01:07 dansmith lyarwood: dm-cache is static partitioning only as far as I know.. i.e. one cache device per block device to be cached
16:02:10 lyarwood dansmith: ack
16:02:32 mriedem oh i see a recent zvm ci job, took 2 hours, failed
16:03:33 dansmith mriedem: no (real) changes to either of them in 2019 either, as far as I can tell. I bet that doesn't mean "they just work and have happy customers" either :)
16:03:53 efried mriedem: +2 but prefer fix-here
16:04:18 dansmith the most recent change to zvm was "add get console support" which was part of the original set of work, IIRC, from feb 2018
16:04:25 mriedem huh zvm ci passed on an earlier patch set in the same change, the latter ps ci failure was due to ssh failing on some guests
16:04:32 mriedem i'm surprised they even enable ssh validatoin in their tempest runs
16:04:46 mriedem yeah zvm in tree is mostly not a usable driver
16:04:53 mriedem create, get console, destroy
16:04:58 dansmith yeah
16:05:21 dansmith I believe I called that as abandonware before we merged :)
16:05:47 mriedem efried: i can do it in there, it just means rebasing and pushing the other 3 changes on top as well
16:05:57 mriedem which likely means i'll be doing rechecks
16:06:01 efried oh
16:06:10 efried then I guess fup it
16:06:24 efried unless it waits too long to get another +2
16:06:50 mriedem yeah if i have to resolve a merge conflict obviously i'd fix there, but i'll fup for now
16:07:04 mriedem dansmith: you just still have s390x ptsd from your early days
16:07:27 mriedem remember, they were doing virtualization since before it was hip
16:07:43 dansmith no, I have ptsd from all of ibm's drivers
16:07:46 melwitt mriedem: we had to ask them to enable ssh validation bc otherwise their config drive stuff could not be tested
16:07:54 mriedem melwitt: ah that's right
16:08:18 mriedem the powervm driver in tree can at least do some things, but i haven't seen ci working for it in years
16:09:13 mriedem looks like maintenance of the out of tree driver has basically been farmed out https://github.com/openstack/nova-powervm/commits/master
16:14:21 openstackgerrit Merged openstack/nova master: Replace time.sleep(10) with service forced_down in tests https://review.opendev.org/692252
16:16:50 openstackgerrit Matt Riedemann proposed openstack/nova master: FUP for Ib62ac0b692eb92a2ed364ec9f486ded05def39ad https://review.opendev.org/693556
16:20:50 openstackgerrit Lee Yarwood proposed openstack/nova master: compute: Use long_rpc_timeout in reserve_block_device_name https://review.opendev.org/693537
16:22:06 openstackgerrit Matt Riedemann proposed openstack/nova master: Convert nova-live-migration job to zuulv3 https://review.opendev.org/693364
16:39:38 openstackgerrit Matt Riedemann proposed openstack/nova master: Remove service_uuids_online_data_migration https://review.opendev.org/693421
16:51:53 sean-k-mooney mriedem: i filed https://bugzilla.redhat.com/show_bug.cgi?id=1761864 to track adding support for it at somepoint but its in our backlog and not prioritised yet.
16:51:53 openstack bugzilla.redhat.com bug 1761864 in openstack-nova "[RFE] Preemtable Instances" [High,New] - Assigned to smooney
16:52:12 sean-k-mooney actully that should not have an assignee
16:53:02 sean-k-mooney dansmith: bcache is pretty stable
16:53:09 sean-k-mooney dansmith: i have been using it for years
16:53:26 dansmith sean-k-mooney: didn't say it wasn't
16:54:24 sean-k-mooney true
16:54:33 sean-k-mooney vs dm-cache i found bcache more flexible
16:54:39 dansmith yup
16:55:10 sean-k-mooney dm-cache also has a longer warmup time but when both caches are hot they perform about the same
16:55:35 sean-k-mooney the bcache dev has moved on to make a bcache file system.
16:56:26 sean-k-mooney bcache is still mainatined upstream in the kernel but they change there focus because tehy though it was feature complete
16:56:55 sean-k-mooney https://bcachefs.org/
16:57:19 sean-k-mooney i would not really use ^ if you like your data yet
16:58:41 sean-k-mooney dansmith: what was the context for the bcache disucssion?
16:58:59 sean-k-mooney is someone asking us to use it to cache remote volumes?
16:59:01 dansmith sean-k-mooney: the spec proposed for volume caching
16:59:46 sean-k-mooney ah that might work for isci volumes
16:59:58 sean-k-mooney we mount those via the kernel right?
17:00:10 sean-k-mooney rather then natively in qemu
17:00:24 dansmith it won't, IMHO, because bcache requires the volumes to be a special format, AFAICT
17:00:30 dansmith which is in the backscroll and the comments on that spec
17:01:19 sean-k-mooney oh right so it did not requrie that orginally
17:01:43 sean-k-mooney but the current version i think require teh backing volume to be converted
17:01:49 dansmith their pre-merge docs all talk about it, so it's been that way for quite a while
17:01:53 dansmith but..yeah
17:02:17 sean-k-mooney well when i first used bcache a few years ago they allowed you to cache an existing volume
17:02:31 sean-k-mooney but they remove that as it lead to data curruption in some cases i think
17:03:14 sean-k-mooney the idea of having fast local storage cache network volumes does have merrit but ya its hard to get right
17:04:09 sean-k-mooney this spec right https://review.opendev.org/#/c/689070/2/specs/ussuri/approved/support-volume-local-cache.rst
17:05:00 dansmith sean-k-mooney: doesn't work for multi-attach, or rbd, or the future where we use qemu-integrated iscsi, and can be done inside the guest with local ssd ephemeral disks
17:05:10 dansmith but yes, I understand caching and why it's desirable
17:05:20 dansmith yes, that's the spec
17:05:20 sean-k-mooney ya just looking at the spec now
17:05:47 sean-k-mooney a better way to arrpoch this woudl be to add a feature to qemu/libvirt
17:06:05 sean-k-mooney so that we could tell qemu to use a device as a cache for another
17:08:18 dansmith sean-k-mooney: yep, but the spec is actually "sell moar intel SSDs through new feature for obscure brand new opensource caching project"
17:09:46 sean-k-mooney funnaily enough i just baught one of those ssds to use a a bcache device in front of the raid5 i use for my cinder lvm backend
17:10:25 mriedem hardware nerd alert
17:11:22 sean-k-mooney hehe it helps hide that my vms are on spinning rust and with random io but its not ssd speed by any means
17:11:44 mriedem you mean you haven't gone plaid yet?
17:12:27 sean-k-mooney plaid ? as in the shirt matail or intels 3d cross point
17:12:33 sean-k-mooney aka optane
17:12:33 mriedem as in spaceballs
17:12:38 mriedem https://www.youtube.com/watch?v=mk7VWcuVOf0
17:14:47 sean-k-mooney ha i should really watch that sometime
17:15:45 mriedem "emergency stop - never use"
17:15:46 mriedem classic
17:15:48 mriedem it's like software
17:58:03 mriedem gate bug fun https://bugs.launchpad.net/nova/+bug/1851871
17:58:03 openstack Launchpad bug 1851871 in OpenStack Compute (nova) "Functional tests intermittently fail with "TypeError: Can't upgrade a READER transaction to a WRITER mid-transaction" during service destroy" [Undecided,New]
21:16:13 openstackgerrit Merged openstack/nova master: Use admin neutron client to see if instance has qos ports https://review.opendev.org/691900
22:29:28 efried okay, where do I get a VM image I can actually do something with?
22:29:44 efried like run python
22:42:28 efried jroll: I'm off PoCing vTPM and am at the point where it would be nice to be able to run $test_program that uses one so I can tell if it's "working". Before I go trying to hack something together (and wind up not even knowing whether it's doing what it's supposed to) do you (or could you obtain/create) something easy?
22:42:38 efried The "hello world" of tpm
#openstack-nova - 2019-11-09
15:08:08 openstackgerrit Matt Riedemann proposed openstack/nova master: WIP: Convert nova-live-migration job to zuulv3 https://review.opendev.org/693364
#openstack-nova - 2019-11-10
14:29:29 openstackgerrit Matt Riedemann proposed openstack/nova master: Remove TODOs around claim_resources_on_destination https://review.opendev.org/693635
14:31:45 openstackgerrit Matt Riedemann proposed openstack/nova master: Remove TODOs around claim_resources_on_destination https://review.opendev.org/693635
14:43:51 openstackgerrit Matt Riedemann proposed openstack/nova master: Resolve TODO in _remove_host_allocations https://review.opendev.org/693636
15:47:46 openstackgerrit Brin Zhang proposed openstack/nova-specs master: Add flavor extra specs group https://review.opendev.org/663563
19:29:27 openstackgerrit Matt Riedemann proposed openstack/nova master: Remove TODOs around claim_resources_on_destination https://review.opendev.org/693635

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