Re: [ovirt-users] storage redundancy in Ovirt

Oh, fence agent works fine if I select ilo4, Thank you for your help! On Sun, Apr 16, 2017 at 8:22 PM Dan Yasny <dyasny(a)gmail.com&gt; wrote: > On Sun, Apr 16, 2017 at 11:19 PM, Konstantin Raskoshnyi < > konrasko(a)gmail.com&gt; wrote: > >> 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! >> >> > It is absolutely necessary for any HA to work properly. There's of course > the "confirm host has been shutdown" option, which serves as an override > for the fence command, but it's manual > > >> 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 >>>>>>>>> >>>>>>>>> >>>>>>>>>