[Gluster-users] Where does Gluster capture the hostnames from?

[Joe Julian]

I disagree about it being "best practice" to lock yourself in to a fixed 
network configuration that can never adapt as business needs change. 
There are other resilient ways of ensuring your hostnames resolve 
consistently (so that your cluster doesn't run loose ;-)).

On 9/23/19 7:38 AM, Strahil wrote:
> Also,
>
> It's more safe to have static entries for your cluster - after all if DNS fails for some reason - you don't want to loose  your cluster.A kind of 'Best Practice'.
>
> Best Regards,
> Strahil NikolovOn Sep 23, 2019 15:01, TomK <tomkcpr at mdevsys.com> wrote:
>> Do I *really* need specific /etc/hosts entries when I have IPA?
>>
>> [root at mdskvm-p01 ~]# cat /etc/hosts
>> 127.0.0.1   localhost localhost.localdomain localhost4
>> localhost4.localdomain4
>> ::1         localhost localhost.localdomain localhost6
>> localhost6.localdomain6
>> [root at mdskvm-p01 ~]#
>>
>> I really shouldn't need too.  ( Ref below, everything resolves fine. )
>>
>> Cheers,
>> TK
>>
>>
>> On 9/23/2019 1:32 AM, Strahil wrote:
>>> Check your /etc/hosts for an entry like:
>>> 192.168.0.60 mdskvm-p01.nix.mds.xyz mdskvm-p01
>>>
>>> Best Regards,
>>> Strahil NikolovOn Sep 23, 2019 06:58, TomK <tomkcpr at mdevsys.com> wrote:
>>>> Hey All,
>>>>
>>>> Take the two hosts below as example.  One host shows NFS Server on
>>>> 192.168.0.60 (FQDN is mdskvm-p01.nix.mds.xyz).
>>>>
>>>> The other shows mdskvm-p02 (FQDN is mdskvm-p02.nix.mds.xyz).
>>>>
>>>> Why is there no consistency or correct hostname resolution?  Where does
>>>> gluster get the hostnames from?
>>>>
>>>>
>>>> [root at mdskvm-p02 glusterfs]# gluster volume status
>>>> Status of volume: mdsgv01
>>>> Gluster process                             TCP Port  RDMA Port  Online  Pid
>>>> ------------------------------------------------------------------------------
>>>> Brick mdskvm-p02.nix.mds.xyz:/mnt/p02-d01/g
>>>> lusterv02                                   49153     0          Y
>>>> 17503
>>>> Brick mdskvm-p01.nix.mds.xyz:/mnt/p01-d01/g
>>>> lusterv01                                   49153     0          Y
>>>> 15044
>>>> NFS Server on localhost                     N/A       N/A        N       N/A
>>>> Self-heal Daemon on localhost               N/A       N/A        Y
>>>> 17531
>>>> NFS Server on 192.168.0.60                  N/A       N/A        N       N/A
>>>> Self-heal Daemon on 192.168.0.60            N/A       N/A        Y
>>>> 15073
>>>>
>>>> Task Status of Volume mdsgv01
>>>> ------------------------------------------------------------------------------
>>>> There are no active volume tasks
>>>>
>>>> [root at mdskvm-p02 glusterfs]#
>>>>
>>>>
>>>>
>>>>
>>>> [root at mdskvm-p01 ~]# gluster volume status
>>>> Status of volume: mdsgv01
>>>> Gluster process                             TCP Port  RDMA Port  Online  Pid
>>>> ------------------------------------------------------------------------------
>>>> Brick mdskvm-p02.nix.mds.xyz:/mnt/p02-d01/g
>>>> lusterv02                                   49153     0          Y
>>>> 17503
>>>> Brick mdskvm-p01.nix.mds.xyz:/mnt/p01-d01/g
>>>> lusterv01                                   49153     0          Y
>>>> 15044
>>>> NFS Server on localhost                     N/A       N/A        N       N/A
>>>> Self-heal Daemon on localhost               N/A       N/A        Y
>>>> 15073
>>>> NFS Server on mdskvm-p02                    N/A       N/A        N       N/A
>>>> Self-heal Daemon on mdskvm-p02              N/A       N/A        Y
>>>> 17531
>>>>
>>>> Task Status of Volume mdsgv01
>>>> ------------------------------------------------------------------------------
>>>> There are no active volume tasks
>>>>
>>>> [root at mdskvm-p01 ~]#
>>>>
>>>>
>>>>
>>>> But when verifying everything all seems fine:
>>>>
>>>>
>>>> (1):
>>>> [root at mdskvm-p01 glusterfs]# dig -x 192.168.0.39
>>>> ;; QUESTION SECTION:
>>>> ;39.0.168.192.in-addr.arpa.     IN      PTR
>>>>
>>>> ;; ANSWER SECTION:
>>>> 39.0.168.192.in-addr.arpa. 1200 IN      PTR     mdskvm-p02.nix.mds.xyz.
>>>> [root at mdskvm-p01 glusterfs]# hostname -f
>>>> mdskvm-p01.nix.mds.xyz
>>>> [root at mdskvm-p01 glusterfs]# hostname -s
>>>> mdskvm-p01
>>>> [root at mdskvm-p01 glusterfs]# hostname
>>>> mdskvm-p01.nix.mds.xyz
>>>> [root at mdskvm-p01 glusterfs]#
>>>>
>>>>
>>>> (2):
>>>>
>>>> [root at mdskvm-p02 glusterfs]# dig -x 192.168.0.60
>>>> ;; QUESTION SECTION:
>>>> ;60.0.168.192.in-addr.arpa.     IN      PTR
>>>>
>>>> ;; ANSWER SECTION:
>>>> 60.0.168.192.in-addr.arpa. 1200 IN      PTR     mdskvm-p01.nix.mds.xyz.
>>>>
>>>> [root at mdskvm-p02 glusterfs]# hostname -s
>>>> mdskvm-p02
>>>> [root at mdskvm-p02 glusterfs]# hostname -f
>>>> mdskvm-p02.nix.mds.xyz
>>>> [root at mdskvm-p02 glusterfs]# hostname
>>>> mdskvm-p02.nix.mds.xyz
>>>> [root at mdskvm-p02 glusterfs]#
>>>>
>>>>
>>>> Gluster version used is:
>>>>
>>>> [root at mdskvm-p01 glusterfs]# rpm -aq|grep -Ei gluster
>>>> glusterfs-server-3.12.15-1.el7.x86_64
>>>> glusterfs-client-xlators-3.12.15-1.el7.x86_64
>>>> glusterfs-rdma-3.12.15-1.el7.x86_64
>>>> glusterfs-3.12.15-1.el7.x86_64
>>>> glusterfs-events-3.12.15-1.el7.x86_64
>>>> libvirt-daemon-driver-storage-gluster-4.5.0-10.el7_6.12.x86_64
>>>> glusterfs-libs-3.12.15-1.el7.x86_64
>>>> glusterfs-fuse-3.12.15-1.el7.x86_64
>>>> glusterfs-geo-replication-3.12.15-1.el7.x86_64
>>>> python2-gluster-3.12.15-1.el7.x86_64
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