Move EBS from Linux 6 to Linux 7

1. Build new server with a temporary name and install RHEL7 on it (by Linux Admin)
It is very important to rename it later to the same server name for EBS apps to work properly.

Linux Admin has to follow Oracle Doc ID 761566.1 (Oracle E-Business Suite Installation and Upgrade Notes Release 12 (12.1.1) for Linux x86-64) to install all required RHEL7 (Red Hat Enterprise Linux 7) components.

$ cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.7 (Maipo)

$ cd /usr/bin
$ ls -altr java*
-rwxr-xr-x 1 root root    5530 Jul 22  2019 javaws.itweb
lrwxrwxrwx 1 root root   24 Feb 13 09:24 javaws -> /etc/alternatives/javaws
lrwxrwxrwx 1 root root   27 Feb 18 19:16 javac -> /usr/java/default/bin/javac
lrwxrwxrwx 1 root root   29 Feb 18 19:16 javadoc -> /usr/java/default/bin/javadoc
lrwxrwxrwx 1 root root   22 Feb 18 19:45 java -> /etc/alternatives/java

$ java -version
openjdk version "1.8.0_232"
OpenJDK Runtime Environment (build 1.8.0_232-b09)
OpenJDK 64-Bit Server VM (build 25.232-b09, mixed mode)
$ javac -version
javac 1.7.0_131

3. Verify the new RHEL7 server

1) Make sure /etc/oraInst.loc is copied over and has right permission.

2) Check all files under /etc/init.d are copied over for auto stop/start EBS services by server's reboot. For example, below two shell scripts stop/start EBS services of two instances.

$ cd /etc/init.d
$ ls -l ebs*
-rwxr-xr-x 1 root root 545 Jun 21  2016 ebs1
-rwxr-xr-x 1 root root 549 Jun 21  2016 ebs2

3) It is good to have /usr/bin/xclock, ftp, sftp, gzip installed.

4) A soft link for libdb-4.3.so under /usr/lib on RHEL7 server is necessary. Otherwise, Apache service will not start on RHEL7 sever by error

httpd: error while loading shared libraries: libdb-4.3.so: cannot open shared object file: No such file or directory

$ cd /usr/lib

$ ls -al libdb*.*
lrwxrwxrwx 1 root root        12    Feb  4 11:30 libdb-4.3.so -> libdb-5.3.so
-rwxr-xr-x 1 root root 1868348    Jan 30  2019 libdb-5.3.so
lrwxrwxrwx 1 root root        12   Dec 10 15:21 libdb-5.so -> libdb-5.3.so
-rw-r--r-- 1 root root         5825   Dec 11 10:52 libdb.so.2

Note: This is different from RHEL6 server, and Apache worked fine.

$ cat /etc/redhat-release

Red Hat Enterprise Linux Server release 6.10 (Santiago)

$ ls -al /usr/lib/libdb*.*

-rw-r--r-- 1 root root 5825 Nov 11  2016 /usr/lib/libdb.so.2

4. Upgrade EBS JDK from JDK 6 to JDK 7 on RHEL6 host. This step is an important pre-step for RHEL7 upgrade, and is not necessary if JDK 7 was used within EBS already. See blow on how to upgrade JDK:

https://erpondb.blogspot.com/2019/12/upgrade-jdk-to-jdk-7-in-ebs-r121.html

$ $ADJVAPRG -version
java version "1.7.0_231"
Java(TM) SE Runtime Environment (build 1.7.0_231-b08)
Java HotSpot(TM) Client VM (build 24.231-b08, mixed mode)

$ echo $IAS_ORACLE_HOME
/path/to/apps/tech_st/10.1.3
$ $IAS_ORACLE_HOME/appsutil/jdk/jre/bin/java -fullversion
java full version "1.7.0_231-b08"

$ echo $ORACLE_HOME
/path/to/apps/tech_st/10.1.2
$ $ORACLE_HOME/jdk/bin/java -fullversion
java full version "1.7.0_231-b08

5. Make final switch

1) Stop EBS apps services on RHEL6 servers
2) Copy all file partitions from RHEL6 servers to RHEL7 servers (using rsync by Linux Admin)
3) Rename new RHEL7 server back to the old server name
(Huge extra work and cloning process are required if EBS server name does not keep the same)
4) Change network DNS with the new IP address for RHEL7 server name
5) Replace old IPs in F5 configuration with the new IP addresses of new EBS hosts
6) Run autoconfig on all EBS nodes on RHEL7 servers
7) Start EBS apps services on RHEL7 servers
8) Make sure file system backup is activated on new servers

Doc ID 761566.1 mentioned two patches. But I did not apply them. I think they may be required if clone process is used to move EBS to new servers.
- 19671435:R12.WIP.B
- 19863797:R12.ENG.C