[ovirt-users] Hosted engine on gluster problem

Simone Tiraboschi stirabos at redhat.com
Mon Aug 29 15:47:18 UTC 2016


On Fri, Aug 26, 2016 at 8:54 AM, Sandro Bonazzola <sbonazzo at redhat.com>
wrote:

>
>
> On Tue, Aug 23, 2016 at 8:44 PM, David Gossage <
> dgossage at carouselchecks.com> wrote:
>
>>
>> On Fri, Apr 15, 2016 at 8:00 AM, Luiz Claudio Prazeres Goncalves <
>> luizcpg at gmail.com> wrote:
>>
>>> I'm not planning to move to ovirt 4 until it gets stable, so would be
>>> great to backport to 3.6 or ,ideally, gets developed on the next release of
>>> 3.6 branch. Considering the urgency (its a single point of failure) x
>>> complexity wouldn't be hard to make the proposed fix.
>>>
>>>
>> Bumping old email sorry.  Looks like https://bugzilla.redhat.com/sh
>> ow_bug.cgi?id=1298693 was finished against 3.6.7 according to that RFE.
>>
>> So does that mean if I add appropriate lines to my
>>  /etc/ovirt-hosted-engine/hosted-engine.conf the next time I restart
>> engine and agent/brokers to mount that storage point it will utilize the
>> backupvol-server features?
>>
>> If so are appropriate settings outlined in docs somewhere?
>>
>> Running ovirt 3.6.7 and gluster 3.8.2 on centos 7 nodes.
>>
>
> Adding Simone
>


First step, you have to edit
/etc/ovirt-hosted-engine/hosted-engine.conf on all your hosted-engine
hosts to ensure that the storage field always point to the same entry
point (host01 for instance)
Then on each host you can add something like:
mnt_options=backupvolfile-server=host02.yourdomain.com:host03.
<http://ost03.ovirt.forest.go.th/>yourdomain.com,fetch-attempts=2,log-level=
WARNING,log-file=/var/log/engine_domain.log

Then check the representation of your storage connection in the table
storage_server_connections
of the engine DB and make sure that connection refers to the entry point
you used in hosted-engine.conf on all your hosts, you have lastly to set
the value of mount_options also here.

Please tune also the value of network.ping-timeout for your glusterFS volume
to avoid this:
 https://bugzilla.redhat.com/show_bug.cgi?id=1319657#c17

You can find other information here:
https://www.ovirt.org/develop/release-management/features/engine/self-hosted-engine-gluster-support/



>
>
>>
>>
>> I'm using today a production environment on top of gluster replica 3 and
>>> this is the only SPF I have.
>>>
>>> Thanks
>>> Luiz
>>>
>>> Em sex, 15 de abr de 2016 03:05, Sandro Bonazzola <sbonazzo at redhat.com>
>>> escreveu:
>>>
>>>> On Thu, Apr 14, 2016 at 7:35 PM, Nir Soffer <nsoffer at redhat.com> wrote:
>>>>
>>>>> On Wed, Apr 13, 2016 at 4:34 PM, Luiz Claudio Prazeres Goncalves
>>>>> <luizcpg at gmail.com> wrote:
>>>>> > Nir, here is the problem:
>>>>> > https://bugzilla.redhat.com/show_bug.cgi?id=1298693
>>>>> >
>>>>> > When you do a hosted-engine --deploy and pick "glusterfs" you don't
>>>>> have a
>>>>> > way to define the mount options, therefore, the use of the
>>>>> > "backupvol-server", however when you create a storage domain from
>>>>> the UI you
>>>>> > can, like the attached screen shot.
>>>>> >
>>>>> >
>>>>> > In the hosted-engine --deploy, I would expect a flow which includes
>>>>> not only
>>>>> > the "gluster" entrypoint, but also the gluster mount options which is
>>>>> > missing today. This option would be optional, but would remove the
>>>>> single
>>>>> > point of failure described on the Bug 1298693.
>>>>> >
>>>>> > for example:
>>>>> >
>>>>> > Existing entry point on the "hosted-engine --deploy" flow
>>>>> > gluster1.xyz.com:/engine
>>>>>
>>>>> I agree, this feature must be supported.
>>>>>
>>>>
>>>> It will, and it's currently targeted to 4.0.
>>>>
>>>>
>>>>
>>>>>
>>>>> > Missing option on the "hosted-engine --deploy" flow :
>>>>> > backupvolfile-server=gluster2.xyz.com,fetch-attempts=3,log-l
>>>>> evel=WARNING,log-file=/var/log/glusterfs/gluster_engine_domain.log
>>>>> >
>>>>> > Sandro, it seems to me a simple solution which can be easily fixed.
>>>>> >
>>>>> > What do you think?
>>>>> >
>>>>> > Regards
>>>>> > -Luiz
>>>>> >
>>>>> >
>>>>> >
>>>>> > 2016-04-13 4:15 GMT-03:00 Sandro Bonazzola <sbonazzo at redhat.com>:
>>>>> >>
>>>>> >>
>>>>> >>
>>>>> >> On Tue, Apr 12, 2016 at 6:47 PM, Nir Soffer <nsoffer at redhat.com>
>>>>> wrote:
>>>>> >>>
>>>>> >>> On Tue, Apr 12, 2016 at 3:05 PM, Luiz Claudio Prazeres Goncalves
>>>>> >>> <luizcpg at gmail.com> wrote:
>>>>> >>> > Hi Sandro, I've been using gluster with 3 external hosts for a
>>>>> while
>>>>> >>> > and
>>>>> >>> > things are working pretty well, however this single point of
>>>>> failure
>>>>> >>> > looks
>>>>> >>> > like a simple feature to implement,but critical to anyone who
>>>>> wants to
>>>>> >>> > use
>>>>> >>> > gluster on production  . This is not hyperconvergency which has
>>>>> other
>>>>> >>> > issues/implications. So , why not have this feature out on 3.6
>>>>> branch?
>>>>> >>> > It
>>>>> >>> > looks like just let vdsm use the 'backupvol-server' option when
>>>>> >>> > mounting the
>>>>> >>> > engine domain and make the property tests.
>>>>> >>>
>>>>> >>> Can you explain what is the problem, and what is the suggested
>>>>> solution?
>>>>> >>>
>>>>> >>> Engine and vdsm already support the backupvol-server option - you
>>>>> can
>>>>> >>> define this option in the storage domain options when you create a
>>>>> >>> gluster
>>>>> >>> storage domain. With this option vdsm should be able to connect to
>>>>> >>> gluster
>>>>> >>> storage domain even if a brick is down.
>>>>> >>>
>>>>> >>> If you don't have this option in engine , you probably cannot add
>>>>> it with
>>>>> >>> hosted
>>>>> >>> engine setup, since for editing it you must put the storage domain
>>>>> in
>>>>> >>> maintenance
>>>>> >>> and if you do this the engine vm will be killed :-) This is is one
>>>>> of
>>>>> >>> the issues with
>>>>> >>> engine managing the storage domain it runs on.
>>>>> >>>
>>>>> >>> I think the best way to avoid this issue, is to add a DNS entry
>>>>> >>> providing the addresses
>>>>> >>> of all the gluster bricks, and use this address for the gluster
>>>>> >>> storage domain. This way
>>>>> >>> the glusterfs mount helper can mount the domain even if one of the
>>>>> >>> gluster bricks
>>>>> >>> are down.
>>>>> >>>
>>>>> >>> Again, we will need some magic from the hosted engine developers to
>>>>> >>> modify the
>>>>> >>> address of the hosted engine gluster domain on existing system.
>>>>> >>
>>>>> >>
>>>>> >> Magic won't happen without a bz :-) please open one describing
>>>>> what's
>>>>> >> requested.
>>>>> >>
>>>>> >>
>>>>> >>>
>>>>> >>>
>>>>> >>> Nir
>>>>> >>>
>>>>> >>> >
>>>>> >>> > Could you add this feature to the next release of 3.6 branch?
>>>>> >>> >
>>>>> >>> > Thanks
>>>>> >>> > Luiz
>>>>> >>> >
>>>>> >>> > Em ter, 12 de abr de 2016 05:03, Sandro Bonazzola <
>>>>> sbonazzo at redhat.com>
>>>>> >>> > escreveu:
>>>>> >>> >>
>>>>> >>> >> On Mon, Apr 11, 2016 at 11:44 PM, Bond, Darryl <
>>>>> dbond at nrggos.com.au>
>>>>> >>> >> wrote:
>>>>> >>> >>>
>>>>> >>> >>> My setup is hyperconverged. I have placed my test results in
>>>>> >>> >>> https://bugzilla.redhat.com/show_bug.cgi?id=1298693
>>>>> >>> >>>
>>>>> >>> >>
>>>>> >>> >> Ok, so you're aware about the limitation of the single point of
>>>>> >>> >> failure.
>>>>> >>> >> If you drop the host referenced in hosted engine configuration
>>>>> for the
>>>>> >>> >> initial setup it won't be able to connect to shared storage
>>>>> even if
>>>>> >>> >> the
>>>>> >>> >> other hosts in the cluster are up since the entry point is down.
>>>>> >>> >> Note that hyperconverged deployment is not supported in 3.6.
>>>>> >>> >>
>>>>> >>> >>
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> Short description of setup:
>>>>> >>> >>>
>>>>> >>> >>> 3 hosts with 2 disks each set up with gluster replica 3 across
>>>>> the 6
>>>>> >>> >>> disks volume name hosted-engine.
>>>>> >>> >>>
>>>>> >>> >>> Hostname hosted-storage configured in /etc//hosts to point to
>>>>> the
>>>>> >>> >>> host1.
>>>>> >>> >>>
>>>>> >>> >>> Installed hosted engine on host1 with the hosted engine
>>>>> storage path
>>>>> >>> >>> =
>>>>> >>> >>> hosted-storage:/hosted-engine
>>>>> >>> >>>
>>>>> >>> >>> Install first engine on h1 successful. Hosts h2 and h3 added
>>>>> to the
>>>>> >>> >>> hosted engine. All works fine.
>>>>> >>> >>>
>>>>> >>> >>> Additional storage and non-hosted engine hosts added etc.
>>>>> >>> >>>
>>>>> >>> >>> Additional VMs added to hosted-engine storage (oVirt Reports
>>>>> VM and
>>>>> >>> >>> Cinder VM). Additional VM's are hosted by other storage -
>>>>> cinder and
>>>>> >>> >>> NFS.
>>>>> >>> >>>
>>>>> >>> >>> The system is in production.
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> Engine can be migrated around with the web interface.
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> - 3.6.4 upgrade released, follow the upgrade guide, engine is
>>>>> >>> >>> upgraded
>>>>> >>> >>> first , new Centos kernel requires host reboot.
>>>>> >>> >>>
>>>>> >>> >>> - Engine placed on h2 -  h3 into maintenance (local) upgrade
>>>>> and
>>>>> >>> >>> Reboot
>>>>> >>> >>> h3 - No issues - Local maintenance removed from h3.
>>>>> >>> >>>
>>>>> >>> >>> - Engine placed on h3 -  h2 into maintenance (local) upgrade
>>>>> and
>>>>> >>> >>> Reboot
>>>>> >>> >>> h2 - No issues - Local maintenance removed from h2.
>>>>> >>> >>>
>>>>> >>> >>> - Engine placed on h3 -h1 into mainteance (local) upgrade and
>>>>> reboot
>>>>> >>> >>> h1 -
>>>>> >>> >>> engine crashes and does not start elsewhere, VM(cinder)  on h3
>>>>> on
>>>>> >>> >>> same
>>>>> >>> >>> gluster volume pauses.
>>>>> >>> >>>
>>>>> >>> >>> - Host 1 takes about 5 minutes to reboot (Enterprise box with
>>>>> all
>>>>> >>> >>> it's
>>>>> >>> >>> normal BIOS probing)
>>>>> >>> >>>
>>>>> >>> >>> - Engine starts after h1 comes back and stabilises
>>>>> >>> >>>
>>>>> >>> >>> - VM(cinder) unpauses itself,  VM(reports) continued fine the
>>>>> whole
>>>>> >>> >>> time.
>>>>> >>> >>> I can do no diagnosis on the 2 VMs as the engine is not
>>>>> available.
>>>>> >>> >>>
>>>>> >>> >>> - Local maintenance removed from h1
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> I don't believe the issue is with gluster itself as the volume
>>>>> >>> >>> remains
>>>>> >>> >>> accessible on all hosts during this time albeit with a missing
>>>>> server
>>>>> >>> >>> (gluster volume status) as each gluster server is rebooted.
>>>>> >>> >>>
>>>>> >>> >>> Gluster was upgraded as part of the process, no issues were
>>>>> seen
>>>>> >>> >>> here.
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> I have been able to duplicate the issue without the upgrade by
>>>>> >>> >>> following
>>>>> >>> >>> the same sort of timeline.
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> ________________________________
>>>>> >>> >>> From: Sandro Bonazzola <sbonazzo at redhat.com>
>>>>> >>> >>> Sent: Monday, 11 April 2016 7:11 PM
>>>>> >>> >>> To: Richard Neuboeck; Simone Tiraboschi; Roy Golan; Martin
>>>>> Sivak;
>>>>> >>> >>> Sahina
>>>>> >>> >>> Bose
>>>>> >>> >>> Cc: Bond, Darryl; users
>>>>> >>> >>> Subject: Re: [ovirt-users] Hosted engine on gluster problem
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> On Mon, Apr 11, 2016 at 9:37 AM, Richard Neuboeck
>>>>> >>> >>> <hawk at tbi.univie.ac.at<mailto:hawk at tbi.univie.ac.at>> wrote:
>>>>> >>> >>> Hi Darryl,
>>>>> >>> >>>
>>>>> >>> >>> I'm still experimenting with my oVirt installation so I tried
>>>>> to
>>>>> >>> >>> recreate the problems you've described.
>>>>> >>> >>>
>>>>> >>> >>> My setup has three HA hosts for virtualization and three
>>>>> machines
>>>>> >>> >>> for the gluster replica 3 setup.
>>>>> >>> >>>
>>>>> >>> >>> I manually migrated the Engine from the initial install host
>>>>> (one)
>>>>> >>> >>> to host three. Then shut down host one manually and
>>>>> interrupted the
>>>>> >>> >>> fencing mechanisms so the host stayed down. This didn't bother
>>>>> the
>>>>> >>> >>> Engine VM at all.
>>>>> >>> >>>
>>>>> >>> >>> Did you move the host one to maintenance before shutting down?
>>>>> >>> >>> Or is this a crash recovery test?
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> To make things a bit more challenging I then shut down host
>>>>> three
>>>>> >>> >>> while running the Engine VM. Of course the Engine was down for
>>>>> some
>>>>> >>> >>> time until host two detected the problem. It started the
>>>>> Engine VM
>>>>> >>> >>> and everything seems to be running quite well without the
>>>>> initial
>>>>> >>> >>> install host.
>>>>> >>> >>>
>>>>> >>> >>> Thanks for the feedback!
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> My only problem is that the HA agent on host two and three
>>>>> refuse to
>>>>> >>> >>> start after a reboot due to the fact that the configuration of
>>>>> the
>>>>> >>> >>> hosted engine is missing. I wrote another mail to
>>>>> >>> >>> users at ovirt.org<mailto:users at ovirt.org>
>>>>> >>> >>> about that.
>>>>> >>> >>>
>>>>> >>> >>> This is weird. Martin,  Simone can you please investigate on
>>>>> this?
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> Cheers
>>>>> >>> >>> Richard
>>>>> >>> >>>
>>>>> >>> >>> On 04/08/2016 01:38 AM, Bond, Darryl wrote:
>>>>> >>> >>> > There seems to be a pretty severe bug with using hosted
>>>>> engine on
>>>>> >>> >>> > gluster.
>>>>> >>> >>> >
>>>>> >>> >>> > If the host that was used as the initial hosted-engine
>>>>> --deploy
>>>>> >>> >>> > host
>>>>> >>> >>> > goes away, the engine VM wil crash and cannot be restarted
>>>>> until
>>>>> >>> >>> > the host
>>>>> >>> >>> > comes back.
>>>>> >>> >>>
>>>>> >>> >>> is this an Hyperconverged setup?
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> >
>>>>> >>> >>> > This is regardless of which host the engine was currently
>>>>> running.
>>>>> >>> >>> >
>>>>> >>> >>> >
>>>>> >>> >>> > The issue seems to be buried in the bowels of VDSM and is
>>>>> not an
>>>>> >>> >>> > issue
>>>>> >>> >>> > with gluster itself.
>>>>> >>> >>>
>>>>> >>> >>> Sahina, can you please investigate on this?
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> >
>>>>> >>> >>> > The gluster filesystem is still accessable from the host
>>>>> that was
>>>>> >>> >>> > running the engine. The issue has been submitted to bugzilla
>>>>> but
>>>>> >>> >>> > the fix is
>>>>> >>> >>> > some way off (4.1).
>>>>> >>> >>> >
>>>>> >>> >>> >
>>>>> >>> >>> > Can my hosted engine be converted to use NFS (using the
>>>>> gluster NFS
>>>>> >>> >>> > server on the same filesystem) without rebuilding my hosted
>>>>> engine
>>>>> >>> >>> > (ie
>>>>> >>> >>> > change domainType=glusterfs to domainType=nfs)?
>>>>> >>> >>>
>>>>> >>> >>> >
>>>>> >>> >>> > What effect would that have on the hosted-engine storage
>>>>> domain
>>>>> >>> >>> > inside
>>>>> >>> >>> > oVirt, ie would the same filesystem be mounted twice or
>>>>> would it
>>>>> >>> >>> > just break.
>>>>> >>> >>> >
>>>>> >>> >>> >
>>>>> >>> >>> > Will this actually fix the problem, does it have the same
>>>>> issue
>>>>> >>> >>> > when
>>>>> >>> >>> > the hosted engine is on NFS?
>>>>> >>> >>> >
>>>>> >>> >>> >
>>>>> >>> >>> > Darryl
>>>>> >>> >>> >
>>>>> >>> >>> >
>>>>> >>> >>> >
>>>>> >>> >>> >
>>>>> >>> >>> > ________________________________
>>>>> >>> >>> >
>>>>> >>> >>> > The contents of this electronic message and any attachments
>>>>> are
>>>>> >>> >>> > intended only for the addressee and may contain legally
>>>>> privileged,
>>>>> >>> >>> > personal, sensitive or confidential information. If you are
>>>>> not the
>>>>> >>> >>> > intended
>>>>> >>> >>> > addressee, and have received this email, any transmission,
>>>>> >>> >>> > distribution,
>>>>> >>> >>> > downloading, printing or photocopying of the contents of this
>>>>> >>> >>> > message or
>>>>> >>> >>> > attachments is strictly prohibited. Any legal privilege or
>>>>> >>> >>> > confidentiality
>>>>> >>> >>> > attached to this message and attachments is not waived, lost
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>>>>> >>> >>> > destroyed by
>>>>> >>> >>> > reason of delivery to any person other than intended
>>>>> addressee. If
>>>>> >>> >>> > you have
>>>>> >>> >>> > received this message and are not the intended addressee you
>>>>> should
>>>>> >>> >>> > notify
>>>>> >>> >>> > the sender by return email and destroy all copies of the
>>>>> message
>>>>> >>> >>> > and any
>>>>> >>> >>> > attachments. Unless expressly attributed, the views
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>>>>> >>> >>> > this email
>>>>> >>> >>> > do not necessarily represent the views of the company.
>>>>> >>> >>> > _______________________________________________
>>>>> >>> >>> > Users mailing list
>>>>> >>> >>> > Users at ovirt.org<mailto:Users at ovirt.org>
>>>>> >>> >>> > http://lists.ovirt.org/mailman/listinfo/users
>>>>> >>> >>> >
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> --
>>>>> >>> >>> /dev/null
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> _______________________________________________
>>>>> >>> >>> Users mailing list
>>>>> >>> >>> Users at ovirt.org<mailto:Users at ovirt.org>
>>>>> >>> >>> http://lists.ovirt.org/mailman/listinfo/users
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>>
>>>>> >>> >>> --
>>>>> >>> >>> Sandro Bonazzola
>>>>> >>> >>> Better technology. Faster innovation. Powered by community
>>>>> >>> >>> collaboration.
>>>>> >>> >>> See how it works at redhat.com<http://redhat.com>
>>>>> >>> >>
>>>>> >>> >>
>>>>> >>> >>
>>>>> >>> >>
>>>>> >>> >> --
>>>>> >>> >> Sandro Bonazzola
>>>>> >>> >> Better technology. Faster innovation. Powered by community
>>>>> >>> >> collaboration.
>>>>> >>> >> See how it works at redhat.com
>>>>> >>> >> _______________________________________________
>>>>> >>> >> Users mailing list
>>>>> >>> >> Users at ovirt.org
>>>>> >>> >> http://lists.ovirt.org/mailman/listinfo/users
>>>>> >>> >
>>>>> >>> >
>>>>> >>> > _______________________________________________
>>>>> >>> > Users mailing list
>>>>> >>> > Users at ovirt.org
>>>>> >>> > http://lists.ovirt.org/mailman/listinfo/users
>>>>> >>> >
>>>>> >>
>>>>> >>
>>>>> >>
>>>>> >>
>>>>> >> --
>>>>> >> Sandro Bonazzola
>>>>> >> Better technology. Faster innovation. Powered by community
>>>>> collaboration.
>>>>> >> See how it works at redhat.com
>>>>> >
>>>>> >
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Sandro Bonazzola
>>>> Better technology. Faster innovation. Powered by community
>>>> collaboration.
>>>> See how it works at redhat.com
>>>>
>>>
>>> _______________________________________________
>>> Users mailing list
>>> Users at ovirt.org
>>> http://lists.ovirt.org/mailman/listinfo/users
>>>
>>>
>>
>
>
> --
> Sandro Bonazzola
> Better technology. Faster innovation. Powered by community collaboration.
> See how it works at redhat.com
>
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