|
IP |
NODE 1 |
NODE 2 |
|
PUBLIC IP |
192.168.10.11 |
192.168.10.12 |
|
PRIVATE IP |
192.168.24.28 |
192.168.24.29 |
|
VIP |
192.168.10.31 |
192.168.10.32 |
|
SCAN IP |
192.168.10.58/192.168.10.59/192.168.10.60 |
Same Across The Cluster |
|
DNS SERVER |
NODE 1 |
NODE 2 |
|
oratest.localdomain |
oratest.localdomain |
oratest2.localdomain |
NOTE: we can use the same server for dns configuration and RAC node 1
configuration.
STEP 1: Since dnsmasq read hostfile. So, make an entry of all the IPs in /etc/hosts file
[root@oratest
~]# cat /etc/hosts
127.0.0.1 localhost.localdomain localhost
# Public
192.168.10.11 oratest oratest.localdomain
192.168.10.12 oratest2 oratest2.localdomain
# Private
192.168.24.28 oratest-priv oratest-priv.localdomain
192.168.24.29 oratest2-priv oratest2-priv.localdomain
# Virtual
192.168.10.31 oratest-vip oratest-vip.localdomain
192.168.10.32 oratest2-vip oratest2-vip.localdomain
# SCAN
192.168.10.58 oratest-scan oratest-scan.localdomain
192.168.10.59 oratest-scan oratest-scan.localdomain
192.168.10.60 oratest-scan oratest-scan.localdomain
STEP 2: Install dnsmasq package
[root@oratest
~]# yum install dnsmasq
Oracle
Linux 8 BaseOS Latest (x86_64)
14 kB/s | 3.6 kB 00:00
Oracle
Linux 8 BaseOS Latest (x86_64)
24 MB/s | 69 MB 00:02
Oracle
Linux 8 Application Stream (x86_64)
50 kB/s | 3.9 kB 00:00
Oracle
Linux 8 Application Stream (x86_64)
23 MB/s | 54 MB 00:02
Latest
Unbreakable Enterprise Kernel Release 7 for Oracle Linux 8 (x86_64)
18 kB/s | 3.0 kB 00:00
Last
metadata expiration check: 0:00:01 ago on Fri 23 Feb 2024 11:33:37 PM IST.
Package
dnsmasq-2.79-26.el8.x86_64 is already installed.
Dependencies
resolved.
===================================================================================================================================================================================================================
Package
Architecture Version
Repository
Size
===================================================================================================================================================================================================================
Upgrading:
dnsmasq
x86_64
2.79-31.el8
ol8_appstream 322 k
Transaction
Summary
===================================================================================================================================================================================================================
Upgrade 1 Package
Total
download size: 322 k
Is
this ok [y/N]: y
Downloading
Packages:
dnsmasq-2.79-31.el8.x86_64.rpm
2.0 MB/s | 322 kB 00:00
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total
2.0 MB/s | 322 kB 00:00
Running
transaction check
Transaction
check succeeded.
Running
transaction test
Transaction
test succeeded.
Running
transaction
Preparing :
1/1
Running scriptlet:
dnsmasq-2.79-31.el8.x86_64
1/1
Running scriptlet:
dnsmasq-2.79-31.el8.x86_64
1/2
Upgrading : dnsmasq-2.79-31.el8.x86_64
1/2
Running scriptlet:
dnsmasq-2.79-31.el8.x86_64
1/2
Running scriptlet:
dnsmasq-2.79-26.el8.x86_64
2/2
Cleanup : dnsmasq-2.79-26.el8.x86_64
2/2
Running scriptlet:
dnsmasq-2.79-26.el8.x86_64
2/2
Verifying : dnsmasq-2.79-31.el8.x86_64
1/2
Verifying : dnsmasq-2.79 26.el8.x86_64
2/2
Upgraded:
dnsmasq-2.79-31.el8.x86_64
Complete!
STEP 3:
Enable dnsmasq service at system boot
[root@oratest
~]# systemctl enable dnsmasq.service
Created
symlink /etc/systemd/system/multi-user.target.wants/dnsmasq.service → /usr/lib/systemd/system/dnsmasq.service.
STEP 4:
create a file under /etc directory to read scan IPs by dns server
[root@oratest ~]# cat /etc/racdns
#
SCAN
192.168.10.58 oratest-scan oratest-scan.localdomain
192.168.10.59 oratest-scan oratest-scan.localdomain
192.168.10.60 oratest-scan oratest-scan.localdomain
STEP 5:
Take backup of /etc/dnsmasq.conf file
[root@oratest
~]# cp /etc/dnsmasq.conf /etc/dnsmasq.conf_orig
[root@oratest
~]# ls -ltr /etc/dnsmasq.*
-rw-r--r--.
1 root dnsmasq 26843 Oct 14 11:17 /etc/dnsmasq.conf
-rw-r--r--.
1 root root 26843 Feb 23 23:37
/etc/dnsmasq.conf_orig
STEP 6: Edit dnsmasq.conf file and adjust below settings
NOTE:
By default, All the above parameter are commented in dnsmasq.conf file , we’ve
to uncomment it prior to set it to a specific values
STEP 7:
Start dnsmasq service
[root@oratest
~]# systemctl start dnsmasq.service
STEP 8:
Validate status of dnsmasq.service
STEP 9: Replace the current
nameserver in /etc/resolv.conf with 127.0.0.1 ( dnsmasq is listening there )
[root@oratest ~]# cat /etc/resolv.conf
#
Generated by NetworkManager
search
localdomain
nameserver
127.0.0.1
STEP 10: Enable chattr in /etc/resolve.conf
[root@oratest ~]# chattr +i /etc/resolv.conf
STEP 11:
Validate Scan IP must run in round-robin fashion in each and every nslookup
