Re: [ovirt-users] hyperconverged question

I can confirm that I did set it up manually, and I did specify backupvol, and in the "manage domain" storage settings, I do have under mount options, backup-volfile-servers=192.168.8.12:192.168.8.13 (and this was done at initial install time). The "used managed gluster" checkbox is NOT checked, and if I check it and save settings, next time I go in it is not checked. --Jim On Fri, Sep 1, 2017 at 2:08 PM, Charles Kozler <ckozleriii(a)gmail.com&gt; wrote: > @ Jim - here is my setup which I will test in a few (brand new cluster) > and report back what I found in my tests > > - 3x servers direct connected via 10Gb > - 2 of those 3 setup in ovirt as hosts > - Hosted engine > - Gluster replica 3 (no arbiter) for all volumes > - 1x engine volume gluster replica 3 manually configured (not using ovirt > managed gluster) > - 1x datatest volume (20gb) replica 3 manually configured (not using > ovirt managed gluster) > - 1x nfstest domain served from some other server in my infrastructure > which, at the time of my original testing, was master domain > > I tested this earlier and all VMs stayed online. However, ovirt cluster > reported DC/cluster down, all VM's stayed up > > As I am now typing this, can you confirm you setup your gluster storage > domain with backupvol? Also, confirm you updated hosted-engine.conf with > backupvol mount option as well? > > On Fri, Sep 1, 2017 at 4:22 PM, Jim Kusznir <jim(a)palousetech.com&gt; wrote: > >> So, after reading the first document twice and the 2nd link thoroughly >> once, I believe that the arbitrator volume should be sufficient and count >> for replica / split brain. EG, if any one full replica is down, and the >> arbitrator and the other replica is up, then it should have quorum and all >> should be good. >> >> I think my underlying problem has to do more with config than the >> replica state. That said, I did size the drive on my 3rd node planning to >> have an identical copy of all data on it, so I'm still not opposed to >> making it a full replica. >> >> Did I miss something here? >> >> Thanks! >> >> On Fri, Sep 1, 2017 at 11:59 AM, Charles Kozler <ckozleriii(a)gmail.com&gt; >> wrote: >> >>> These can get a little confusing but this explains it best: >>> https://gluster.readthedocs.io/en/latest/Administrator >>> %20Guide/arbiter-volumes-and-quorum/#replica-2-and-replica-3-volumes >>> >>> Basically in the first paragraph they are explaining why you cant have >>> HA with quorum for 2 nodes. Here is another overview doc that explains some >>> more >>> >>> http://openmymind.net/Does-My-Replica-Set-Need-An-Arbiter/ >>> >>> From my understanding arbiter is good for resolving split brains. >>> Quorum and arbiter are two different things though quorum is a mechanism to >>> help you **avoid** split brain and the arbiter is to help gluster resolve >>> split brain by voting and other internal mechanics (as outlined in link 1). >>> How did you create the volume exactly - what command? It looks to me like >>> you created it with 'gluster volume create replica 2 arbiter 1 {....}' per >>> your earlier mention of "replica 2 arbiter 1". That being said, if you did >>> that and then setup quorum in the volume configuration, this would cause >>> your gluster to halt up since quorum was lost (as you saw until you >>> recovered node 1) >>> >>> As you can see from the docs, there is still a corner case for getting >>> in to split brain with replica 3, which again, is where arbiter would help >>> gluster resolve it >>> >>> I need to amend my previous statement: I was told that arbiter volume >>> does not store data, only metadata. I cannot find anything in the docs >>> backing this up however it would make sense for it to be. That being said, >>> in my setup, I would not include my arbiter or my third node in my ovirt VM >>> cluster component. I would keep it completely separate >>> >>> >>> On Fri, Sep 1, 2017 at 2:46 PM, Jim Kusznir <jim(a)palousetech.com&gt; >>> wrote: >>> >>>> I'm now also confused as to what the point of an arbiter is / what it >>>> does / why one would use it. >>>> >>>> On Fri, Sep 1, 2017 at 11:44 AM, Jim Kusznir <jim(a)palousetech.com&gt; >>>> wrote: >>>> >>>>> Thanks for the help! >>>>> >>>>> Here's my gluster volume info for the data export/brick (I have 3: >>>>> data, engine, and iso, but they're all configured the same): >>>>> >>>>> Volume Name: data >>>>> Type: Replicate >>>>> Volume ID: e670c488-ac16-4dd1-8bd3-e43b2e42cc59 >>>>> Status: Started >>>>> Snapshot Count: 0 >>>>> Number of Bricks: 1 x (2 + 1) = 3 >>>>> Transport-type: tcp >>>>> Bricks: >>>>> Brick1: ovirt1.nwfiber.com:/gluster/brick2/data >>>>> Brick2: ovirt2.nwfiber.com:/gluster/brick2/data >>>>> Brick3: ovirt3.nwfiber.com:/gluster/brick2/data (arbiter) >>>>> Options Reconfigured: >>>>> performance.strict-o-direct: on >>>>> nfs.disable: on >>>>> user.cifs: off >>>>> network.ping-timeout: 30 >>>>> cluster.shd-max-threads: 8 >>>>> cluster.shd-wait-qlength: 10000 >>>>> cluster.locking-scheme: granular >>>>> cluster.data-self-heal-algorithm: full >>>>> performance.low-prio-threads: 32 >>>>> features.shard-block-size: 512MB >>>>> features.shard: on >>>>> storage.owner-gid: 36 >>>>> storage.owner-uid: 36 >>>>> cluster.server-quorum-type: server >>>>> cluster.quorum-type: auto >>>>> network.remote-dio: enable >>>>> cluster.eager-lock: enable >>>>> performance.stat-prefetch: off >>>>> performance.io-cache: off >>>>> performance.read-ahead: off >>>>> performance.quick-read: off >>>>> performance.readdir-ahead: on >>>>> server.allow-insecure: on >>>>> [root@ovirt1 ~]# >>>>> >>>>> >>>>> all 3 of my brick nodes ARE also members of the virtualization >>>>> cluster (including ovirt3). How can I convert it into a full replica >>>>> instead of just an arbiter? >>>>> >>>>> Thanks! >>>>> --Jim >>>>> >>>>> On Fri, Sep 1, 2017 at 9:09 AM, Charles Kozler <ckozleriii(a)gmail.com&gt; >>>>> wrote: >>>>> >>>>>> @Kasturi - Looks good now. Cluster showed down for a moment but VM's >>>>>> stayed up in their appropriate places. Thanks! >>>>>> >>>>>> < Anyone on this list please feel free to correct my response to Jim >>>>>> if its wrong> >>>>>> >>>>>> @ Jim - If you can share your gluster volume info / status I can >>>>>> confirm (to the best of my knowledge). From my understanding, If you setup >>>>>> the volume with something like 'gluster volume set <vol> group virt' this >>>>>> will configure some quorum options as well, Ex: >>>>>> http://i.imgur.com/Mya4N5o.png >>>>>> >>>>>> While, yes, you are configured for arbiter node you're still losing >>>>>> quorum by dropping from 2 -> 1. You would need 4 node with 1 being arbiter >>>>>> to configure quorum which is in effect 3 writable nodes and 1 arbiter. If >>>>>> one gluster node drops, you still have 2 up. Although in this case, you >>>>>> probably wouldnt need arbiter at all >>>>>> >>>>>> If you are configured, you can drop quorum settings and just let >>>>>> arbiter run since you're not using arbiter node in your VM cluster part (I >>>>>> believe), just storage cluster part. When using quorum, you need > 50% of >>>>>> the cluster being up at one time. Since you have 3 nodes with 1 arbiter, >>>>>> you're actually losing 1/2 which == 50 which == degraded / hindered gluster >>>>>> >>>>>> Again, this is to the best of my knowledge based on other quorum >>>>>> backed software....and this is what I understand from testing with gluster >>>>>> and ovirt thus far >>>>>> >>>>>> On Fri, Sep 1, 2017 at 11:53 AM, Jim Kusznir <jim(a)palousetech.com&gt; >>>>>> wrote: >>>>>> >>>>>>> Huh...Ok., how do I convert the arbitrar to full replica, then? I >>>>>>> was misinformed when I created this setup. I thought the arbitrator held >>>>>>> enough metadata that it could validate or refudiate any one replica (kinda >>>>>>> like the parity drive for a RAID-4 array). I was also under the impression >>>>>>> that one replica + Arbitrator is enough to keep the array online and >>>>>>> functional. >>>>>>> >>>>>>> --Jim >>>>>>> >>>>>>> On Fri, Sep 1, 2017 at 5:22 AM, Charles Kozler < >>>>>>> ckozleriii(a)gmail.com&gt; wrote: >>>>>>> >>>>>>>> @ Jim - you have only two data volumes and lost quorum. Arbitrator >>>>>>>> only stores metadata, no actual files. So yes, you were running in degraded >>>>>>>> mode so some operations were hindered. >>>>>>>> >>>>>>>> @ Sahina - Yes, this actually worked fine for me once I did that. >>>>>>>> However, the issue I am still facing, is when I go to create a new gluster >>>>>>>> storage domain (replica 3, hyperconverged) and I tell it "Host to use" and >>>>>>>> I select that host. If I fail that host, all VMs halt. I do not recall this >>>>>>>> in 3.6 or early 4.0. This to me makes it seem like this is "pinning" a node >>>>>>>> to a volume and vice versa like you could, for instance, for a singular >>>>>>>> hyperconverged to ex: export a local disk via NFS and then mount it via >>>>>>>> ovirt domain. But of course, this has its caveats. To that end, I am using >>>>>>>> gluster replica 3, when configuring it I say "host to use: " node 1, then >>>>>>>> in the connection details I give it node1:/data. I fail node1, all VMs >>>>>>>> halt. Did I miss something? >>>>>>>> >>>>>>>> On Fri, Sep 1, 2017 at 2:13 AM, Sahina Bose <sabose(a)redhat.com&gt; >>>>>>>> wrote: >>>>>>>> >>>>>>>>> To the OP question, when you set up a gluster storage domain, you >>>>>>>>> need to specify backup-volfile-servers=<server2>:<server3> where >>>>>>>>> server2 and server3 also have bricks running. When server1 is down, and the >>>>>>>>> volume is mounted again - server2 or server3 are queried to get the gluster >>>>>>>>> volfiles. >>>>>>>>> >>>>>>>>> @Jim, if this does not work, are you using 4.1.5 build with >>>>>>>>> libgfapi access? If not, please provide the vdsm and gluster mount logs to >>>>>>>>> analyse >>>>>>>>> >>>>>>>>> If VMs go to paused state - this could mean the storage is not >>>>>>>>> available. You can check "gluster volume status <volname>" to see if >>>>>>>>> atleast 2 bricks are running. >>>>>>>>> >>>>>>>>> On Fri, Sep 1, 2017 at 11:31 AM, Johan Bernhardsson < >>>>>>>>> johan(a)kafit.se&gt; wrote: >>>>>>>>> >>>>>>>>>> If gluster drops in quorum so that it has less votes than it >>>>>>>>>> should it will stop file operations until quorum is back to normal.If i >>>>>>>>>> rember it right you need two bricks to write for quorum to be met and that >>>>>>>>>> the arbiter only is a vote to avoid split brain. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Basically what you have is a raid5 solution without a spare. And >>>>>>>>>> when one disk dies it will run in degraded mode. And some raid systems will >>>>>>>>>> stop the raid until you have removed the disk or forced it to run anyway. >>>>>>>>>> >>>>>>>>>> You can read up on it here: https://gluster.readthed >>>>>>>>>> ocs.io/en/latest/Administrator%20Guide/arbiter-volumes-and-q >>>>>>>>>> uorum/ >>>>>>>>>> >>>>>>>>>> /Johan >>>>>>>>>> >>>>>>>>>> On Thu, 2017-08-31 at 22:33 -0700, Jim Kusznir wrote: >>>>>>>>>> >>>>>>>>>> Hi all: >>>>>>>>>> >>>>>>>>>> Sorry to hijack the thread, but I was about to start essentially >>>>>>>>>> the same thread. >>>>>>>>>> >>>>>>>>>> I have a 3 node cluster, all three are hosts and gluster nodes >>>>>>>>>> (replica 2 + arbitrar). I DO have the mnt_options=backup-volfile-servers= >>>>>>>>>> set: >>>>>>>>>> >>>>>>>>>> storage=192.168.8.11:/engine >>>>>>>>>> mnt_options=backup-volfile-servers=192.168.8.12:192.168.8.13 >>>>>>>>>> >>>>>>>>>> I had an issue today where 192.168.8.11 went down. ALL VMs >>>>>>>>>> immediately paused, including the engine (all VMs were running on >>>>>>>>>> host2:192.168.8.12). I couldn't get any gluster stuff working until host1 >>>>>>>>>> (192.168.8.11) was restored. >>>>>>>>>> >>>>>>>>>> What's wrong / what did I miss? >>>>>>>>>> >>>>>>>>>> (this was set up "manually" through the article on setting up >>>>>>>>>> self-hosted gluster cluster back when 4.0 was new..I've upgraded it to 4.1 >>>>>>>>>> since). >>>>>>>>>> >>>>>>>>>> Thanks! >>>>>>>>>> --Jim >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On Thu, Aug 31, 2017 at 12:31 PM, Charles Kozler < >>>>>>>>>> ckozleriii(a)gmail.com&gt; wrote: >>>>>>>>>> >>>>>>>>>> Typo..."Set it up and then failed that **HOST**" >>>>>>>>>> >>>>>>>>>> And upon that host going down, the storage domain went down. I >>>>>>>>>> only have hosted storage domain and this new one - is this why the DC went >>>>>>>>>> down and no SPM could be elected? >>>>>>>>>> >>>>>>>>>> I dont recall this working this way in early 4.0 or 3.6 >>>>>>>>>> >>>>>>>>>> On Thu, Aug 31, 2017 at 3:30 PM, Charles Kozler < >>>>>>>>>> ckozleriii(a)gmail.com&gt; wrote: >>>>>>>>>> >>>>>>>>>> So I've tested this today and I failed a node. Specifically, I >>>>>>>>>> setup a glusterfs domain and selected "host to use: node1". Set it up and >>>>>>>>>> then failed that VM >>>>>>>>>> >>>>>>>>>> However, this did not work and the datacenter went down. My >>>>>>>>>> engine stayed up, however, it seems configuring a domain to pin to a host >>>>>>>>>> to use will obviously cause it to fail >>>>>>>>>> >>>>>>>>>> This seems counter-intuitive to the point of glusterfs or any >>>>>>>>>> redundant storage. If a single host has to be tied to its function, this >>>>>>>>>> introduces a single point of failure >>>>>>>>>> >>>>>>>>>> Am I missing something obvious? >>>>>>>>>> >>>>>>>>>> On Thu, Aug 31, 2017 at 9:43 AM, Kasturi Narra < >>>>>>>>>> knarra(a)redhat.com&gt; wrote: >>>>>>>>>> >>>>>>>>>> yes, right. What you can do is edit the hosted-engine.conf file >>>>>>>>>> and there is a parameter as shown below [1] and replace h2 and h3 with your >>>>>>>>>> second and third storage servers. Then you will need to restart >>>>>>>>>> ovirt-ha-agent and ovirt-ha-broker services in all the nodes . >>>>>>>>>> >>>>>>>>>> [1] 'mnt_options=backup-volfile-servers=<h2>:<h3>' >>>>>>>>>> >>>>>>>>>> On Thu, Aug 31, 2017 at 5:54 PM, Charles Kozler < >>>>>>>>>> ckozleriii(a)gmail.com&gt; wrote: >>>>>>>>>> >>>>>>>>>> Hi Kasturi - >>>>>>>>>> >>>>>>>>>> Thanks for feedback >>>>>>>>>> >>>>>>>>>> > If cockpit+gdeploy plugin would be have been used then that >>>>>>>>>> would have automatically detected glusterfs replica 3 volume created during >>>>>>>>>> Hosted Engine deployment and this question would not have been asked >>>>>>>>>> >>>>>>>>>> Actually, doing hosted-engine --deploy it too also auto detects >>>>>>>>>> glusterfs. I know glusterfs fuse client has the ability to failover >>>>>>>>>> between all nodes in cluster, but I am still curious given the fact that I >>>>>>>>>> see in ovirt config node1:/engine (being node1 I set it to in hosted-engine >>>>>>>>>> --deploy). So my concern was to ensure and find out exactly how engine >>>>>>>>>> works when one node goes away and the fuse client moves over to the other >>>>>>>>>> node in the gluster cluster >>>>>>>>>> >>>>>>>>>> But you did somewhat answer my question, the answer seems to be >>>>>>>>>> no (as default) and I will have to use hosted-engine.conf and change the >>>>>>>>>> parameter as you list >>>>>>>>>> >>>>>>>>>> So I need to do something manual to create HA for engine on >>>>>>>>>> gluster? Yes? >>>>>>>>>> >>>>>>>>>> Thanks so much! >>>>>>>>>> >>>>>>>>>> On Thu, Aug 31, 2017 at 3:03 AM, Kasturi Narra < >>>>>>>>>> knarra(a)redhat.com&gt; wrote: >>>>>>>>>> >>>>>>>>>> Hi, >>>>>>>>>> >>>>>>>>>> During Hosted Engine setup question about glusterfs volume is >>>>>>>>>> being asked because you have setup the volumes yourself. If cockpit+gdeploy >>>>>>>>>> plugin would be have been used then that would have automatically detected >>>>>>>>>> glusterfs replica 3 volume created during Hosted Engine deployment and this >>>>>>>>>> question would not have been asked. >>>>>>>>>> >>>>>>>>>> During new storage domain creation when glusterfs is selected >>>>>>>>>> there is a feature called 'use managed gluster volumes' and upon checking >>>>>>>>>> this all glusterfs volumes managed will be listed and you could choose the >>>>>>>>>> volume of your choice from the dropdown list. >>>>>>>>>> >>>>>>>>>> There is a conf file called /etc/hosted-engine/hosted-engine.conf >>>>>>>>>> where there is a parameter called backup-volfile-servers="h1:h2" and if one >>>>>>>>>> of the gluster node goes down engine uses this parameter to provide ha / >>>>>>>>>> failover. >>>>>>>>>> >>>>>>>>>> Hope this helps !! >>>>>>>>>> >>>>>>>>>> Thanks >>>>>>>>>> kasturi >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On Wed, Aug 30, 2017 at 8:09 PM, Charles Kozler < >>>>>>>>>> ckozleriii(a)gmail.com&gt; wrote: >>>>>>>>>> >>>>>>>>>> Hello - >>>>>>>>>> >>>>>>>>>> I have successfully created a hyperconverged hosted engine setup >>>>>>>>>> consisting of 3 nodes - 2 for VM's and the third purely for storage. I >>>>>>>>>> manually configured it all, did not use ovirt node or anything. Built the >>>>>>>>>> gluster volumes myself >>>>>>>>>> >>>>>>>>>> However, I noticed that when setting up the hosted engine and >>>>>>>>>> even when adding a new storage domain with glusterfs type, it still asks >>>>>>>>>> for hostname:/volumename >>>>>>>>>> >>>>>>>>>> This leads me to believe that if that one node goes down (ex: >>>>>>>>>> node1:/data), then ovirt engine wont be able to communicate with that >>>>>>>>>> volume because its trying to reach it on node 1 and thus, go down >>>>>>>>>> >>>>>>>>>> I know glusterfs fuse client can connect to all nodes to provide >>>>>>>>>> failover/ha but how does the engine handle this? >>>>>>>>>> >>>>>>>>>> _______________________________________________ >>>>>>>>>> Users mailing list >>>>>>>>>> Users(a)ovirt.org >>>>>>>>>> http://lists.ovirt.org/mailman/listinfo/users >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> _______________________________________________ >>>>>>>>>> Users mailing list >>>>>>>>>> Users(a)ovirt.org >>>>>>>>>> http://lists.ovirt.org/mailman/listinfo/users >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> _______________________________________________ >>>>>>>>>> Users mailing listUsers@ovirt.orghttp://lists.ovirt.org/mailman/listinfo/users >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> _______________________________________________ >>>>>>>>>> Users mailing list >>>>>>>>>> Users(a)ovirt.org >>>>>>>>>> http://lists.ovirt.org/mailman/listinfo/users >>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> Users mailing list >>>>>>>> Users(a)ovirt.org >>>>>>>> http://lists.ovirt.org/mailman/listinfo/users >>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >