How to Create Red Hat HA Cluster Part -IV

This is the last part of clustering series post regarding Red Hat HA cluster. In this post, HA NFS will be created in the cluster.

Creating a Fail-over Domain:

[root@node01 ~]# ccs -h localhost --addfailoverdomain NFS
[root@node01 ~]# ccs -h localhost --addfailoverdomainnode NFS node01-hb.cls.local
[root@node01 ~]# ccs -h localhost --addfailoverdomainnode NFS node02-hb.cls.local

Creating Resources.

As you see the section nfs client we specify the target *(all). It is not secure configuration, so you should specify network addresses that you want to allow.

[root@node01 ~]# ccs -h localhost --addresource lvm name=nfs-halvm vg_name=vgcls_nfs lv_name=lvcls_nfs
[root@node01 ~]# ccs -h localhost --addresource fs name=nfs-fs mountpoint="/mnt/nfs-export" fstype="ext4" device="/dev/vgcls_nfs/lvcls_nfs" force_fsck="0" force_unmount="0"
[root@node01 ~]# ccs -h localhost --addresource nfsserver name=nfs-server
[root@node01 ~]# ccs -h localhost --addresource nfsclient name=nfs-client options="rw,no_root_squash" target="*"
[root@node01 ~]# ccs -h localhost --addresource ip address="192.168.122.20" monitor_link="1"

Creating Service Groups

[root@node01 ~]# ccs -h localhost --addservice  HANFS domain="NFS" nfslock=1 exclusive=0 recovery=relocate autostart=1
[root@node01 ~]# ccs -h localhost --addsubservice HANFS ip ref=192.168.122.20
[root@node01 ~]# ccs -h localhost --addsubservice HANFS lvm ref=nfs-halvm
[root@node01 ~]# ccs -h localhost --addsubservice HANFS lvm:fs ref=nfs-fs
[root@node01 ~]# ccs -h localhost --addsubservice HANFS lvm:fs:nfsserver ref=nfs-server
[root@node01 ~]# ccs -h localhost --addsubservice HANFS lvm:fs:nfsserver:nfsclient ref=nfs-client

Sync cluster configuration to the other nodes.

[root@node01 ~]# ccs -h localhost --sync --activate

Final Cluster Configuration:

[root@node01 ~]# ccs -h localhost --getconf
<cluster config_version="127" name="ankara-cluster">  
  <fence_daemon/>  
  <clusternodes>    
    <clusternode name="node01-hb.cls.local" nodeid="1">      
      <fence>        
        <method name="FMET_XVM">          
          <device domain="node01" name="FDEV_XVM1"/>          
        </method>        
      </fence>      
    </clusternode>    
    <clusternode name="node02-hb.cls.local" nodeid="2">      
      <fence>        
        <method name="FMET_XVM">          
          <device domain="node02" name="FDEV_XVM2"/>          
        </method>        
      </fence>      
    </clusternode>    
  </clusternodes>  
  <cman expected_votes="1" two_node="1"/>  
  <fencedevices>    
    <fencedevice agent="fence_xvm" name="FDEV_XVM1"/>    
    <fencedevice agent="fence_xvm" name="FDEV_XVM2"/>    
  </fencedevices>  
  <rm>    
    <failoverdomains>      
      <failoverdomain name="name=httpd" nofailback="0" ordered="0" restricted="0"/>      
      <failoverdomain name="NFS" nofailback="0" ordered="0" restricted="0">        
        <failoverdomainnode name="node01-hb.cls.local"/>        
        <failoverdomainnode name="node02-hb.cls.local"/>        
      </failoverdomain>      
    </failoverdomains>    
    <resources>      
      <clusterfs device="UUID=996a0360-1895-2c53-b4ed-876151027b61" fstype="gfs2" mountpoint="/data/httpd" name="httpdgfs2"/>      
      <ip address="192.168.122.10" monitor_link="yes" sleeptime="10"/>      
      <lvm lv_name="lvcls_nfs" name="nfs-halvm" vg_name="vgcls_nfs"/>      
      <fs device="/dev/vgcls_nfs/lvcls_nfs" force_fsck="0" force_unmount="0" fstype="ext4" mountpoint="/mnt/nfs-export" name="nfs-fs"/>      
      <nfsserver name="nfs-server"/>      
      <nfsclient name="nfs-client" options="rw,no_root_squash" target="*"/>      
      <ip address="192.168.122.20" monitor_link="1"/>      
    </resources>    
    <service domain="httpd" name="httpd-resources" recovery="relocate">      
      <ip ref="192.168.122.10">        
        <clusterfs ref="httpdgfs2"/>        
      </ip>      
    </service>    
    <service autostart="1" domain="NFS" exclusive="0" name="HANFS" nfslock="1" recovery="relocate">      
      <ip ref="192.168.122.20"/>      
      <lvm ref="nfs-halvm">        
        <fs ref="nfs-fs">          
          <nfsserver ref="nfs-server">            
            <nfsclient ref="nfs-client"/>            
          </nfsserver>          
        </fs>        
      </lvm>      
    </service>    
  </rm>  
  <quorumd label="qdisk"/>  
</cluster>

Cluster Status:

[root@node01 ~]# clustat 
Cluster Status for ankara-cluster @ Sat Jan 13 19:54:54 2018
Member Status: Quorate

 Member Name                                                     ID   Status
 ------ ----                                                     ---- ------
 node01-hb.cls.local                                                 1 Online, Local, rgmanager
 node02-hb.cls.local                                                 2 Online, rgmanager
 /dev/block/8:16                                                     0 Online, Quorum Disk

 Service Name                                                  Owner (Last)                                                  State         
 ------- ----                                                  ----- ------                                                  -----         
 service:HANFS                                                 node01-hb.cls.local                                           started       
 service:httpd-resources                                       node01-hb.cls.local                                           started       
[root@node01 ~]# 


df -hP

#on node01
#df -hP 
/dev/mapper/vgcls_httpd-lv_httpd 1020M  131M  890M  13% /data/httpd
/dev/mapper/vgcls_nfs-lvcls_nfs   988M  1.4M  936M   1% /mnt/nfs-export

Cluster IP NFS HA

[root@node01 ~]# ping -c3 192.168.122.20
PING 192.168.122.20 (192.168.122.20) 56(84) bytes of data.
64 bytes from 192.168.122.20: icmp_seq=1 ttl=64 time=0.035 ms
64 bytes from 192.168.122.20: icmp_seq=2 ttl=64 time=0.023 ms
64 bytes from 192.168.122.20: icmp_seq=3 ttl=64 time=0.042 ms

Mounting HA NFS:

[root@KVMHOST ~]# mount.nfs nfscls:/mnt/nfs-export /mnt/nfscls/
[root@oc7133075241 ~]# df -hP
(...omitted)
Filesystem                           Size  Used Avail Use% Mounted on

nfscls:/mnt/nfs-export               988M  1.3M  936M   1% /mnt/nfscls

Migrating Cluster Service to Other Node:

[root@node01 ~]# clusvcadm 
usage: clusvcadm [command]

Resource Group Control Commands:
  -v                     Display version and exit
  -d <group>             Disable <group>.  This stops a group
                         until an administrator enables it again,
                         the cluster loses and regains quorum, or
                         an administrator-defined event script
                         explicitly enables it again.
  -e <group>             Enable <group>
  -e <group> -F          Enable <group> according to failover
                         domain rules (deprecated; always the
                         case when using central processing)
  -e <group> -m <member> Enable <group> on <member>
  -r <group> -m <member> Relocate <group> [to <member>]
                         Stops a group and starts it on another
                         cluster member.
  -M <group> -m <member> Migrate <group> to <member>
                         (e.g. for live migration of VMs)
  -q                     Quiet operation
  -R <group>             Restart a group in place.
  -s <group>             Stop <group>.  This temporarily stops
                         a group.  After the next group or
                         or cluster member transition, the group
                         will be restarted (if possible).
  -Z <group>             Freeze resource group.  This prevents
                         transitions and status checks, and is 
                         useful if an administrator needs to 
                         administer part of a service without 
                         stopping the whole service.
  -U <group>             Unfreeze (thaw) resource group.  Restores
                         a group to normal operation.
  -c <group>             Convalesce (repair, fix) resource group.
                         Attempts to start failed, non-critical 
                         resources within a resource group.
Resource Group Locking (for cluster Shutdown / Debugging):
  -l                     Lock local resource group managers.
                         This prevents resource groups from
                         starting.
  -S                     Show lock state
  -u                     Unlock resource group managers.
                         This allows resource groups to start.

Migrating httpd-resources service to node02.

[root@node01 ~]# clusvcadm -r httpd-resources -m node02-hb.cls.local
Trying to relocate service:httpd-resources to node02-hb.cls.local...Success
service:httpd-resources is now running on node02-hb.cls.local

[root@node01 ~]# clustat 
Cluster Status for ankara-cluster @ Sat Jan 13 20:11:10 2018
Member Status: Quorate

 Member Name                                                     ID   Status
 ------ ----                                                     ---- ------
 node01-hb.cls.local                                                 1 Online, Local, rgmanager
 node02-hb.cls.local                                                 2 Online, rgmanager
 /dev/block/8:16                                                     0 Online, Quorum Disk

 Service Name                                                  Owner (Last)                                                  State         
 ------- ----                                                  ----- ------                                                  -----         
 service:HANFS                                                 node01-hb.cls.local                                           started       
 service:httpd-resources                                       node02-hb.cls.local                                           started

Testing

[root@oc7133075241 ~]# curl http://ankara-cluster
<h1> Hello Ankara-Cluster</h1>
<h2>Tue, 14 2017</h2>

Cluster Operations:

#Checking fence agent. You can run on this command only on the master node.
[root@node01 ~]# fence_check 
fence_check run at Sat Jan 13 20:05:49 CET 2018 pid: 1022
Testing node01-hb.cls.local method 1: success
Testing node02-hb.cls.local method 1: success

Finding Master Nodeid:

[root@node01 ~]# cman_tool services
fence domain
member count  2
victim count  0
victim now    0
master nodeid 1
wait state    none
members       1 2 

dlm lockspaces
name          httpdgfs2
id            0x2b180060
flags         0x00000008 fs_reg
change        member 1 joined 1 remove 0 failed 0 seq 1,1
members       1 

name          rgmanager
id            0x5231f3eb
flags         0x00000000 
change        member 2 joined 1 remove 0 failed 0 seq 2,2
members       1 2 

name          clvmd
id            0x4104eefa
flags         0x00000000 
change        member 2 joined 1 remove 0 failed 0 seq 2,2
members       1 2 

gfs mountgroups
name          httpdgfs2
id            0xf8e8df07
flags         0x00000048 mounted
change        member 1 joined 1 remove 0 failed 0 seq 1,1
members       1 

 

Showing Nodes:

[root@node01 ~]# cman_tool nodes
Node  Sts   Inc   Joined               Name
   0   M      0   2018-01-13 19:41:11  /dev/block/8:16
   1   M    728   2018-01-13 19:41:06  node01-hb.cls.local
   2   M    732   2018-01-13 19:41:30  node02-hb.cls.local

 

 

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