Re: [ovirt-users] storage redundancy in Ovirt

Makes sense. I was trying to set it up, but doesn't work with our staging hardware. We have old ilo100, I'll try again. Thanks!

On Sun, Apr 16, 2017 at 8:18 PM Dan Yasny <dyasny(a)gmail.com&gt; wrote: > On Sun, Apr 16, 2017 at 11:15 PM, Konstantin Raskoshnyi < > konrasko(a)gmail.com&gt; wrote: > >> Fence agent under each node? >> > > When you configure a host, there's the power management tab, where you > need to enter the bmc details for the host. If you don't have fencing > enabled, how do you expect the system to make sure a host running a service > is actually down (and it is safe to start HA services elsewhere), and not, > for example, just unreachable by the engine? How do you avoid a splitbraid > -> SBA ? > > >> >> On Sun, Apr 16, 2017 at 8:14 PM Dan Yasny <dyasny(a)gmail.com&gt; wrote: >> >>> On Sun, Apr 16, 2017 at 11:13 PM, Konstantin Raskoshnyi < >>> konrasko(a)gmail.com&gt; wrote: >>> >>>> "Corner cases"? >>>> I tried to simulate crash of SPM server and ovirt kept trying to >>>> reistablished connection to the failed node. >>>> >>> >>> Did you configure fencing? >>> >>> >>>> >>>> >>>> On Sun, Apr 16, 2017 at 8:10 PM Dan Yasny <dyasny(a)gmail.com&gt; wrote: >>>> >>>>> On Sun, Apr 16, 2017 at 7:29 AM, Nir Soffer <nsoffer(a)redhat.com&gt; >>>>> wrote: >>>>> >>>>>> On Sun, Apr 16, 2017 at 2:05 PM Dan Yasny <dyasny(a)redhat.com&gt; wrote: >>>>>> >>>>>>> >>>>>>> >>>>>>> On Apr 16, 2017 7:01 AM, "Nir Soffer" <nsoffer(a)redhat.com&gt; wrote: >>>>>>> >>>>>>> On Sun, Apr 16, 2017 at 4:17 AM Dan Yasny <dyasny(a)gmail.com&gt; wrote: >>>>>>> >>>>>>>> When you set up a storage domain, you need to specify a host to >>>>>>>> perform the initial storage operations, but once the SD is defined, it's >>>>>>>> details are in the engine database, and all the hosts get connected to it >>>>>>>> directly. If the first host you used to define the SD goes down, all other >>>>>>>> hosts will still remain connected and work. SPM is an HA service, and if >>>>>>>> the current SPM host goes down, SPM gets started on another host in the DC. >>>>>>>> In short, unless your actual NFS exporting host goes down, there is no >>>>>>>> outage. >>>>>>>> >>>>>>> >>>>>>> There is no storage outage, but if you shutdown the spm host, the >>>>>>> spm host >>>>>>> will not move to a new host until the spm host is online again, or >>>>>>> you confirm >>>>>>> manually that the spm host was rebooted. >>>>>>> >>>>>>> >>>>>>> In a properly configured setup the SBA should take care of that. >>>>>>> That's the whole point of HA services >>>>>>> >>>>>> >>>>>> In some cases like power loss or hardware failure, there is no way >>>>>> to start >>>>>> the spm host, and the system cannot recover automatically. >>>>>> >>>>> >>>>> There are always corner cases, no doubt. But in a normal situation. >>>>> where an SPM host goes down because of a hardware failure, it gets fenced, >>>>> other hosts contend for SPM and start it. No surprises there. >>>>> >>>>> >>>>>> >>>>>> Nir >>>>>> >>>>>> >>>>>>> >>>>>>> >>>>>>> Nir >>>>>>> >>>>>>> >>>>>>>> >>>>>>>> On Sat, Apr 15, 2017 at 1:53 PM, Konstantin Raskoshnyi < >>>>>>>> konrasko(a)gmail.com&gt; wrote: >>>>>>>> >>>>>>>>> Hi Fernando, >>>>>>>>> I see each host has direct connection nfs mount, but yes, if main >>>>>>>>> host to which I connected nfs storage going down the storage becomes >>>>>>>>> unavailable and all vms are down >>>>>>>>> >>>>>>>>> >>>>>>>>> On Sat, Apr 15, 2017 at 10:37 AM FERNANDO FREDIANI < >>>>>>>>> fernando.frediani(a)upx.com&gt; wrote: >>>>>>>>> >>>>>>>>>> Hello Konstantin. >>>>>>>>>> >>>>>>>>>> That doesn`t make much sense make a whole cluster depend on a >>>>>>>>>> single host. From what I know any host talk directly to NFS Storage Array >>>>>>>>>> or whatever other Shared Storage you have. >>>>>>>>>> Have you tested that host going down if that affects the other >>>>>>>>>> with the NFS mounted directlly in a NFS Storage array ? >>>>>>>>>> >>>>>>>>>> Fernando >>>>>>>>>> >>>>>>>>>> 2017-04-15 12:42 GMT-03:00 Konstantin Raskoshnyi < >>>>>>>>>> konrasko(a)gmail.com&gt;: >>>>>>>>>> >>>>>>>>>>> In ovirt you have to attach storage through specific host. >>>>>>>>>>> If host goes down storage is not available. >>>>>>>>>>> >>>>>>>>>>> On Sat, Apr 15, 2017 at 7:31 AM FERNANDO FREDIANI < >>>>>>>>>>> fernando.frediani(a)upx.com&gt; wrote: >>>>>>>>>>> >>>>>>>>>>>> Well, make it not go through host1 and dedicate a storage >>>>>>>>>>>> server for running NFS and make both hosts connect to it. >>>>>>>>>>>> In my view NFS is much easier to manage than any other type of >>>>>>>>>>>> storage, specially FC and iSCSI and performance is pretty much the same, so >>>>>>>>>>>> you won`t get better results other than management going to other type. >>>>>>>>>>>> >>>>>>>>>>>> Fernando >>>>>>>>>>>> >>>>>>>>>>>> 2017-04-15 5:25 GMT-03:00 Konstantin Raskoshnyi < >>>>>>>>>>>> konrasko(a)gmail.com&gt;: >>>>>>>>>>>> >>>>>>>>>>>>> Hi guys, >>>>>>>>>>>>> I have one nfs storage, >>>>>>>>>>>>> it's connected through host1. >>>>>>>>>>>>> host2 also has access to it, I can easily migrate vms between >>>>>>>>>>>>> them. >>>>>>>>>>>>> >>>>>>>>>>>>> The question is - if host1 is down - all infrastructure is >>>>>>>>>>>>> down, since all traffic goes through host1, >>>>>>>>>>>>> is there any way in oVirt to use redundant storage? >>>>>>>>>>>>> >>>>>>>>>>>>> Only glusterfs? >>>>>>>>>>>>> >>>>>>>>>>>>> Thanks >>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> _______________________________________________ >>>>>>>>>>>>> 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 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 >>>>>>> >>>>>>> >>>>>>>