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Re: [EXTERNAL] Re: List of Queries related to RHV
by Nir Soffer 15 Nov '18

15 Nov '18

On Wed, Oct 17, 2018 at 5:03 PM Mahesh Falmari <Mahesh.Falmari(a)veritas.com> wrote: > Thanks for the prompt response on these queries. We have few follow-up > queries mentioned inline. > > > > Thanks & Regards, > Mahesh Falmari > > > > *From:* Yaniv Lavi <ylavi(a)redhat.com> > *Sent:* Tuesday, October 16, 2018 7:19 PM > *To:* Mahesh Falmari <Mahesh.Falmari(a)veritas.com> > *Cc:* Nir Soffer <nsoffer(a)redhat.com>; Erez, Daniel <derez(a)redhat.com>; > Tal Nisan <tnisan(a)redhat.com>; Pavan Chavva <pchavva(a)redhat.com>; devel < > devel(a)ovirt.org>; James Olson <James.Olson(a)veritas.com>; Navin Tah < > Navin.Tah(a)veritas.com>; Sudhakar Paulzagade < > Sudhakar.Paulzagade(a)veritas.com>; Abhay Marode <Abhay.Marode(a)veritas.com>; > Suchitra Herwadkar <Suchitra.Herwadkar(a)veritas.com>; Nirmalya Sirkar < > Nirmalya.Sirkar(a)veritas.com>; Abhijeet Barve <Abhijeet.Barve(a)veritas.com> > *Subject:* [EXTERNAL] Re: List of Queries related to RHV > > > > > *YANIV LAVI* > > SENIOR TECHNICAL PRODUCT MANAGER > > Red Hat Israel Ltd. <https://www.redhat.com/> > > 34 Jerusalem Road, Building A, 1st floor > > Ra'anana, Israel 4350109 > > ylavi(a)redhat.com T: +972-9-7692306/8272306 F: +972-9-7692223 > IM: ylavi > > <https://red.ht/sig> > > *TRIED. TESTED. TRUSTED.* <https://redhat.com/trusted> > > @redhatnews <https://twitter.com/redhatnews> Red Hat <https://www.linkedin.com/company/red-hat> Red Hat <https://www.facebook.com/RedHatInc> > > > > On Tue, Oct 16, 2018 at 4:35 PM Mahesh Falmari <Mahesh.Falmari(a)veritas.com> > wrote: > > Hi Nir, > > We have few queries with respect to RHV which we would like to understand > from you. > > > > *1. Does RHV maintains the virtual machine configuration file in back end?* > > Just like we have configuration files for other hypervisors like for > VMware it is .vmx and for Hyper-V, it is .vmcx which captures most of the > virtual machine configuration information in that. On the similar lines, > does RHV also maintains such file? If not, what is the other way to get all > the virtual machine configuration information from a single API? > > > > There is a OVF storage, but this is not meant for consumption. > Right, this is only for internal use. ... > *3. Do we have any version associated with the virtual machine?* > > Just like we have hardware version in case of VMware and virtual machine > version in case of Hyper-V, does RHV also associate any such version with > virtual machine? > > > > The HW version is based on the VM machine type. > > [Mahesh] Can you please elaborate more on this? How simply VM machine > type going to determine it’s version? > Arik, can you answer this? Regarding backup, I think you need to store the vm configuration at the time of the backup regardless of having a version or not. The amount of data is very small. > *4. Is it possible to create virtual machines with QCOW2 as base disks > instead of RAW?* > > We would like to understand if there are any use cases customers prefer > creating virtual machines from QCOW2 as base disks instead of RAW ones. > > > > That is a possibility in cases of thin disk on file storage. > > [Mahesh] Can you please elaborate more on this? > Using the UI you can use qcow2 format only for thin disks on block storage. Using the SDK you can also create qcow2 image on thin file based storage. You can see examples here: https://github.com/oVirt/ovirt-engine-sdk/blob/78c3d5bd14eeb93ef72ec31d775f… In 4.3 we plan to support qcow2 image format for both thin and preallocated disks to allow change block tracking for incremental backup. See html: https://github.com/oVirt/ovirt-site/blob/bc51f4a7867d9c7e3797da6da1d19e111c… > > > *5. RHV Deployment* > > What kind of deployments you have come across in the field? Does customers > scale their infrastructure by adding more datacenters/clusters/nodes or > they add more RHV managers? What scenarios trigger having more than one RHV > manager? > > > > We are all kind with oVirt. I depends on the use case. > I don't know about any stats from users, but the general idea is: - one engine - 1 or more DCs - 1 or more storage domains in a DC - 1 or more clusters per DCs - 1 or more hosts per cluster The theoretical limit is 2000 hosts per DC (limited by sanlock), but the practical limit is much lower. I don't think we have setups with more than 200 hosts. Martin, do you have more info on this? > *6. Image transfer* > > We are trying to download disk chunks using multiple threads to improve > performance of reading data from RHV. Downloading 2 disk chunks > simultaneously via threads should take approximately the same time. > > This is much more complicated to calculate. > But from our observations this takes roughly 1.5 times. > > It sounds like a reasonable speed up. Can RHVM server requests in parallel, > > Yes > if so are there any settings that need to be tweaked? > > We don't have any settings related to concurrency. > Here is an example: > Request 1 for chunk 1 from thread 1, Range: bytes=0-1023 > Request 2 for chunk 2 from thread 2, Range: bytes=1024-2047 > Takes roughly 1.5 seconds, whereas a single request would take 1 second. > Expecting it to take just around 1 second. > > 1.5 seconds for reading 1024 bytes? > [Mahesh] Seeking response to this query. > > The throughout you will get depends on many things: - are you communicating with the proxy (using proxy_url) or the daemon (transfer_url)? Accessing the daemon directly will be faster. - are you running on the same host as the daemon performing the transfer? - if you run on the same host, are you using unix socket? (15% improvement expected) - are you using the same connection per thread for entire transfer (huge improvement when doing small requests) - which version are you testing? we support keep alive connections only since 1.4.x. - are you using big enough requests? you will get best performance if you use one big request per thread - network bandwidth - storage speed For best throughput when downloading single disk, you should use multiple threads, each downloading one part of an image, but I'm not sure it worth the time to optimize this since backup are expected the run in the same time anyway, and you will quickly reach the storage limit while downloading disks for multiple vms on multiple hosts in the same time. I suggest testing the expected use case, not single download. > *7. Free and Thaw operation* > > For cinder based VM, API recommended for FS consistent backup. > > - POST /api/vms/<ID>/freezefilesystems > - POST /api/vms/<ID>/thawfilesystems > > Why do we need this whereas it is not required for other storage? > > Creating a snapshot does this for you in a case where you have the oVirt > guest agent install on the guest. > > [Mahesh] Thanks, we would also like to understand is there a way to > control crash/app consistent snapshots through REST APIs? > snapshots are always consistent if you have qemu guest agent installed, and the guest is using the guest agent scripts properly. Without the guest agent, or if it is not configured properly, file system will have to recover after restore, in the same way it recovers after power failure. To be able to resume a vm to the same state when the snapshot was done you need to include memory in the snapshot, but this make the snapshot much slower, depending on the amount of guest memory, and require huge amount of space, so I don't think it makes sense for backup. Regarding REST API, Arik can add more info about this. Nir

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[CQ ovirt master] [ovirt-engine] - not passing for 10 days
by Ehud Yonasi 15 Nov '18

15 Nov '18

Hey, I've seen that CQ Master is not passing ovirt-engine for 10 days and fails on test suite called restore_vm0_networking here's a snap error regarding it: https://pastebin.com/7msEYqKT Link to a sample job with the error: http://jenkins.ovirt.org/job/ovirt-master_change-queue-tester/11113/artifac… Can some1 have a look at it and help to resolve the issue?

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Unassigned bugs for targeted releases
by Sandro Bonazzola 15 Nov '18

15 Nov '18

Hi, we have 32 bugs targeted to a release but without an assignee: https://bugzilla.redhat.com/buglist.cgi?quicksearch=classification%3Aovirt%… Can you please review the list and ensure someone will work on them or drop the target if they're not going to be worked on? Thanks -- SANDRO BONAZZOLA MANAGER, SOFTWARE ENGINEERING, EMEA R&D RHV Red Hat EMEA <https://www.redhat.com/> sbonazzo(a)redhat.com <https://red.ht/sig>

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Proposing Shmuel Melamud as a Virt backend maintainer
by Michal Skrivanek 14 Nov '18

14 Nov '18

Hi all, I’d like to propose Shmuel as a backend maintainer for the virt area. He’s a good candidate with his 200+ patches and insight into complex parts of VM pools, templates, q35 support, v2v, sparsify... Feel free to bother him more with review requests;) Thanks, michal

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Please Stop merging to ovirt-engine master branch
by Dafna Ron 14 Nov '18

14 Nov '18

Hi , Please stop merging to ovirt-engine master branch as we have been failing on different regressions for the last 11 days. I do not want any other regressions to be introduced until we can properly catch them which means we need to fix the current issues before merging more changes. Thanks, Dafna

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vdsm has been tagged (v4.30.2)
by Milan Zamazal 14 Nov '18

14 Nov '18

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VDSM-Gluster python 3 compatibility
by Kaustav Majumder 14 Nov '18

14 Nov '18

Hi all, I have been working on making vdsm-gluster python 3 compatible. I had some queries regarding the tool used for getting storage devices info. Till now vdsm uses python blivet for getting the device tree information. I am not sure if blivet is compatible with python 3 so I had two propositions which I want some advice on. 1) Using lsblk and parsing the output 2) Using ansible modules locally in the vdsm hosts. Although I feel the 2nd way will add more dependencies to the project but it can help us in the long run to add more functionality easily. Thanks, Kaustav

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Re: [CentOS-devel] SIGs: Possibility to drop EOL content at 7.6.1810 release time
by Sandro Bonazzola 13 Nov '18

13 Nov '18

Il giorno ven 2 nov 2018 alle ore 12:33 Niels de Vos <ndevos(a)redhat.com> ha scritto: > On Thu, Nov 01, 2018 at 11:01:51AM +0200, Anssi Johansson wrote: > ... > > For reference and inspiration, here are some directories from > > mirror.centos.org, including both up-to-date content and potentially EOL > > content. SIGs should review the list to make sure these directories can > > be copied over to 7.6.1810 when that time comes. Making the decisions > > now would save a bit of time at 7.6.1810 release time. > > > .. > > > storage/x86_64/gluster-3.10 > > storage/x86_64/gluster-3.12 > > The above two can be dropped (also for CentOS 6). This includes the > centos-release-gluster310 and centos-release-gluster-312 packages in > Extras. > > Can we keep 3.12? It's still consumed by oVirt 4.2. Adding oVirt devel team, just in case we'll need urgently to rebase on newer Gluster on CentOS 7.6 GA or block upgrade to CentOS 7.6 from oVirt side till we figure out how to handle. > > storage/x86_64/gluster-4.0 > > storage/x86_64/gluster-4.1 > > storage/x86_64/gluster-5 > > These three are still maintained. > > Thanks, > Niels > _______________________________________________ > CentOS-devel mailing list > CentOS-devel(a)centos.org > https://lists.centos.org/mailman/listinfo/centos-devel > -- SANDRO BONAZZOLA MANAGER, SOFTWARE ENGINEERING, EMEA R&D RHV Red Hat EMEA <https://www.redhat.com/> sbonazzo(a)redhat.com <https://red.ht/sig>

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Upstream package missing release suffix
by Ales Musil 13 Nov '18

13 Nov '18

Hello, ovirt-lldp-labeler is missing release suffix in nightly build [1]. This has been fixed some time ago in [2]. Any idea what could be wrong? Thank you. Regards, Ales. [1] https://plain.resources.ovirt.org/pub/ovirt-master-snapshot/rpm/el7/noarch/ [2] https://gerrit.ovirt.org/c/94616/ -- ALES MUSIL Associate Software Engineer - rhv network Red Hat EMEA <https://www.redhat.com/> amusil(a)redhat.com IM: amusil <https://red.ht/sig>

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[VDSM] Proposing Denis as vdsm gluster maintainer
by Nir Soffer 13 Nov '18

13 Nov '18

Hi all, Denis is practically maintaining vdsm gluster code in the recent years, and it is time to make this official. Please ack, Nir

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