Hi, Can you point me to some document that help me to understand how gluster client work ? Related to ovirt will be helpful.
Thanks, ~Rohit On Thu, May 18, 2017 at 11:54 AM, knarra <kna...@redhat.com> wrote: > On 05/18/2017 10:35 AM, TranceWorldLogic . wrote: > > Thanks, > Would you also explain about my 2nd question ? > > let say hostB mounted glusterFS partition by using backup vol (e.g. hostB) > and after some time Host A come online, will GlusterFS client (mount) > automatically switch to Host A ? > > mount will not switch automatically to Host A . > > In an ideal case i.e with out using backup-vol-file-server option if host > B goes down, you mount will not be accessible since host B went down and df > -TH or mount does not show the volume or it says "Transport End point not > connected". > > Take the case where using backup-volfile-server option. If host B goes > down, your mount will still be accessible since there is > backup-volfile-server and df -TH or mount still shows that volume is > mounted using Host B, but all the internal requests will be served through > Host A. > > > > On Thu, May 18, 2017 at 9:43 AM, knarra <kna...@redhat.com> wrote: > >> Hi, >> >> backup-volfile-servers is mainly used to avoid SPOF. For example take >> a scenario where you have Host A and Host B and when you try to mount a >> glusterfs volume using Host A with backup-volfile-servers specified, if >> Host A is not accessible, mount will happen with Host B which is specified >> in backup-volfile-server. backup-volfile-servers are mainly used to fetch >> the volfile from gluster and has nothing to do with data sync. >> >> data syncing comes as part of replicate feature in glusterfs where >> say for example, you have two Hosts Host A and Host B with replica volume >> configured, if Host A goes down for sometime, all the writes happens on >> Host B and when Host A comes up data gets synced to HostA. >> >> Hope this helps !!!! >> >> Thanks >> kasturi >> >> >> On 05/17/2017 11:31 PM, TranceWorldLogic . wrote: >> >> Hi, >> >> Before trying out, I want to understand how glusterfs will react for >> below scenario. >> Please help me. >> >> Let consider I have two host hostA and hostB >> I have setup replica volume on hostA and hostB. (consider as storage >> domain for DATA in ovirt). >> I have configure data domain mount command with backup server option >> (backup-volfile-server) as hostB (I mean main server as hostA and backup as >> hostB) >> >> 1> As I understood, VDSM execute mount command on both hostA and >> hostB.(for creating data domain) >> 2> That mean, HostB glusterFS CLIENT will communicate with main server >> (hostA). >> (Please correct me if I am wrong here.) >> 3> Let say HostA got down (say shutdown, power off scenario) >> 4> Due to backup option I will have data domain available on HostB. >> (Now glusterFS CLIENT on HostB will start communicating with HostB >> GlusterFS SERVER). >> 5> Now let say HostA comes up. >> 6> Will it sync all data from HostB to HostA glusterFS server ? >> (as per doc, yes, i not tried yet, want to confirm my understanding) >> 7> Will glusterFS CLIENT on HostB start communicate with main server >> (HostA) ? >> >> Please let me know, I am new to glusterFS. >> >> Thanks, >> ~Rohit >> >> >> _______________________________________________ >> Users mailing >> listUsers@ovirt.orghttp://lists.ovirt.org/mailman/listinfo/users >> >>
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