Oracle Database Client 12c Release 1 on Oracle Linux 8

Open the listing on AWS Marketplace, choose View purchase options and then Subscribe. When the subscription is active, choose Launch your software. In Version, pick Oracle Database Client 12c Release 1 on OL 8.

Choose your Region, an instance type (m5.large is recommended), your key pair and a security group that opens port 22 from your own networks only. Then launch the instance.

The instance is ready about two minutes after launch.

Replace <ami-id> with the AMI ID of this version in your Region, and replace the other angle-bracket values with your own. The command requires IMDSv2:

aws ec2 run-instances \
  --image-id <ami-id> \
  --instance-type m5.large \
  --key-name <key-name> \
  --subnet-id <subnet-id> \
  --security-group-ids <security-group-id> \
  --metadata-options HttpTokens=required,HttpEndpoint=enabled \
  --tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=oracle-client-12-1}]'

When the instance is running, retrieve its public address:

aws ec2 describe-instances --instance-ids <instance-id> --query "Reservations[].Instances[].PublicIpAddress" --output text

The SSH user for Oracle Database Client 12c Release 1 on Oracle Linux 8 is ec2-user. Connect with your key pair:

ssh -i <your-key.pem> ec2-user@<public-ip>

Check that the first boot verification ran:

systemctl status sac-oracle-client-firstboot.service --no-pager | head -5 sudo cat /var/log/sac/oracle-client-firstboot.log

The unit is active (exited) with status=0/SUCCESS. The log records how many files of the Oracle home were checked:

● sac-oracle-client-firstboot.service - sac: verify the Oracle Database Client home on first boot Loaded: loaded (/etc/systemd/system/sac-oracle-client-firstboot.service; enabled; vendor preset: disabled) Active: active (exited) since Sat 2026-10-24 01:54:37 EDT; 1min 15s ago Process: 6961 ExecStart=/usr/local/sbin/sac-oracle-client-firstboot (code=exited, status=0/SUCCESS) Main PID: 6961 (code=exited, status=0/SUCCESS) 2026-10-24T05:54:35Z first boot verification started 2026-10-24T05:54:37Z verified 443 files of the Oracle home; SQL*Plus 12.1.0.2.0

If the unit failed, read /root/oracle-client-FIRSTBOOT-FAILED.txt and contact support.

Your login shell already has the Oracle environment. The command blocks in this guide also source /etc/profile.d/oracle-client.sh first, so they work the same in a non-login shell:

. /etc/profile.d/oracle-client.sh echo "ORACLE_HOME=$ORACLE_HOME" echo "TNS_ADMIN=$TNS_ADMIN" sqlplus -V ls "$ORACLE_HOME/bin" | grep -xE 'sqlplus|sqlldr|tnsping|exp|imp|expdp|impdp|adrci|orapki|mkstore' | tr '\n' ' '; echo

ORACLE_HOME=/u01/app/oracle/product/12.1.0/client_1 TNS_ADMIN=/u01/app/oracle/product/12.1.0/client_1/network/admin SQL*Plus: Release 12.1.0.2.0 Production adrci exp expdp imp impdp mkstore orapki sqlldr sqlplus tnsping

The release line shows the exact release. 12.1.0.2.0 is the 12c Release 1 base release (Oracle's full installation media for 12c Release 1), with no Oracle patch applied.

These are the key paths on the image:

• /u01/app/oracle/product/12.1.0/client_1: ORACLE_HOME
• /u01/app/oracle: ORACLE_BASE
• $ORACLE_HOME/network/admin: TNS_ADMIN, which holds sqlnet.ora and tnsnames.ora
• $ORACLE_HOME/jdbc/lib/ojdbc7.jar: JDBC Thin driver for Java 7 and 8 (ojdbc6.jar for Java 6)
• $ORACLE_HOME/lib/libclntsh.so: OCI client library (C, C++, Python python-oracledb thick mode, Perl, PHP OCI8)
• $ORACLE_HOME/lib/libocci.so.12.1: OCCI C++ client library
• $ORACLE_HOME/lib/libsqora.so.12.1: ODBC driver
• /u01/app/oraInventory: Oracle central inventory
• /usr/share/doc/sac/oracle-client-12-1/README.txt: a summary of this image

The image carries a self-test that repeats the first boot checks and proves the client works end to end without a database. It covers Oracle Net name resolution, a connection attempt that reaches the network layer, the exact listening ports, SELinux, every SSH setting, a root login shell that keeps the system libraries, the accounts and the absence of a compiler. Run it:

sudo /usr/local/sbin/sac-oracle-client-selftest

PASS: first-boot verification marker present PASS: no first-boot failure note PASS: Oracle home matches the build manifest (443 files) PASS: login shell: sqlplus -V = 12.1.0.2.0 PASS: wrapper (non-login): sqlplus -V = 12.1.0.2.0 PASS: tnsping: unknown alias refused (TNS-03505) PASS: sqlplus: no listener on this instance (ORA-12541) PASS: only TCP 22 listens PASS: no Oracle listener process PASS: SELinux enforcing PASS: sshd -T passwordauthentication no PASS: sshd -T permitrootlogin no PASS: sshd -T pubkeyauthentication yes PASS: sshd -T x11forwarding no PASS: sshd -T kbdinteractiveauthentication no PASS: sshd -T challengeresponseauthentication no PASS: sshd -T permitemptypasswords no PASS: sshd -T allowtcpforwarding yes PASS: sshd -T maxauthtries 4 PASS: sshd -T clientaliveinterval 300 PASS: sshd -T clientalivecountmax 3 PASS: sshd -T logingracetime 60 PASS: root login shell: no LD_LIBRARY_PATH, system libraries not shadowed (python XML parser loads) PASS: no account carries a password hash, locked or not PASS: no compiler (gcc, cc, c++, g++, make) on the PATH PASS: no core dump or crash report ORACLE_CLIENT_SELFTEST_OK

TNS-03505 and ORA-12541 are the expected answers. The self-test asks for an alias that does not exist, and it connects to port 1521 on the instance itself, where no listener runs.

sqlnet.ora resolves names through tnsnames.ora first and then EZCONNECT (host:port/service), so you can connect without any configuration, or give each database a short alias. Review the shipped files:

. /etc/profile.d/oracle-client.sh grep -v '^#' "$TNS_ADMIN/sqlnet.ora" cat "$TNS_ADMIN/tnsnames.ora"

NAMES.DIRECTORY_PATH = (TNSNAMES, EZCONNECT) SQLNET.EXPIRE_TIME = 10 SQLNET.OUTBOUND_CONNECT_TIMEOUT = 60
# sac Oracle Database Client 12c Release 1 - Oracle Net service names.
# Add one entry per database, for example:
#
# MYDB =
# (DESCRIPTION =
# (ADDRESS = (PROTOCOL = TCP)(HOST = db.example.com)(PORT = 1521))
# (CONNECT_DATA = (SERVER = DEDICATED)(SERVICE_NAME = ORCLPDB1))
# )

The oracle software owner owns these files, so edit them with sudo. To add an alias, append an entry with your database's host, port and service name:

sudo tee -a /u01/app/oracle/product/12.1.0/client_1/network/admin/tnsnames.ora > /dev/null <<'TNS' MYDB = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = <db-host>)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED)(SERVICE_NAME = <service-name>)) ) TNS tnsping MYDB

tnsping resolves the alias and contacts the database listener. It ends with OK (<n> msec) when the listener answers. If it reports TNS-12535 or times out, the network path to the database (security groups, network ACLs, routes) does not allow the connection.

To keep your own tnsnames.ora elsewhere, set TNS_ADMIN to that directory in your shell profile.

Connect with the alias, or connect directly with EZCONNECT. SQL*Plus prompts for the password, which keeps it out of your shell history and the process list:

sqlplus <db-user>@MYDB sqlplus <db-user>@//<db-host>:1521/<service-name>

For Amazon RDS for Oracle, <db-host> is the DB instance endpoint shown in the RDS console, and <service-name> is the database name (ORCL by default). After you connect, run:

SELECT banner_full FROM v$version; SELECT sys_context('USERENV', 'SERVICE_NAME') FROM dual;

Never put a password on the command line (sqlplus user/password@db). Every user of the instance can see it in the process list.

For unattended scripts, use an Oracle wallet (a secure external password store) instead. Create it with mkstore in a directory only your account can read. Add WALLET_LOCATION and SQLNET.WALLET_OVERRIDE = TRUE to your own sqlnet.ora, and connect with sqlplus /@MYDB. The image ships no wallet, so every wallet you create is your instance's own.

Oracle Net traffic is not encrypted unless the client and the server agree to encrypt it. sqlnet.ora carries commented settings for both methods:

• Oracle Native Network Encryption. Uncomment the SQLNET.ENCRYPTION_CLIENT and SQLNET.CRYPTO_CHECKSUM_CLIENT lines (REQUIRED, AES256 and SHA256) to refuse any unencrypted session. The database must accept encryption. Amazon RDS for Oracle enables it with the NATIVE_NETWORK_ENCRYPTION option.
• TLS (TCPS). Create a wallet holding your database's CA certificate with orapki, point WALLET_LOCATION at it, and use (PROTOCOL = TCPS) and the database's TLS port in the alias. Amazon RDS for Oracle provides TLS with its SSL option and publishes its CA certificates.

List the commented settings:

. /etc/profile.d/oracle-client.sh grep -n 'ENCRYPTION\|CRYPTO\|WALLET' "$TNS_ADMIN/sqlnet.ora"

9:# SQLNET.ENCRYPTION_CLIENT = REQUIRED 10:# SQLNET.ENCRYPTION_TYPES_CLIENT = (AES256) 11:# SQLNET.CRYPTO_CHECKSUM_CLIENT = REQUIRED 12:# SQLNET.CRYPTO_CHECKSUM_TYPES_CLIENT = (SHA256) 14:# WALLET_LOCATION = (SOURCE = (METHOD = FILE) (METHOD_DATA = (DIRECTORY = /path/to/your/wallet)))

Edit sqlnet.ora with sudo, as in step 6.

If the database is reachable only through a bastion, an SSH tunnel also works. Open the tunnel with ssh -N -L 1521:<db-host>:1521 ec2-user@<bastion>, then connect to //localhost:1521/<service-name>.

A login shell has the environment from /etc/profile.d/oracle-client.sh. Scripts and cron jobs do not read it. For that reason, sqlplus, sqlldr and tnsping are also installed as wrappers in /usr/local/bin that set the environment for that one command:

cat /usr/local/bin/sqlplus env -i PATH=/usr/local/bin:/usr/bin:/bin sqlplus -V

#!/bin/bash
# sac Oracle Database Client 12c Release 1 wrapper: sqlplus from any shell (scripts, cron), environment scoped to this call export ORACLE_BASE=/u01/app/oracle export ORACLE_HOME=/u01/app/oracle/product/12.1.0/client_1 export TNS_ADMIN=${TNS_ADMIN:-/u01/app/oracle/product/12.1.0/client_1/network/admin} export NLS_LANG=${NLS_LANG:-AMERICAN_AMERICA.AL32UTF8} export LD_LIBRARY_PATH=/u01/app/oracle/product/12.1.0/client_1/lib${LD_LIBRARY_PATH:+:${LD_LIBRARY_PATH}} exec /u01/app/oracle/product/12.1.0/client_1/bin/sqlplus "$@" SQL*Plus: Release 12.1.0.2.0 Production

For other Oracle tools in a script, source the profile first (. /etc/profile.d/oracle-client.sh). Applications use the libraries directly:

• Java: add $ORACLE_HOME/jdbc/lib/ojdbc7.jar (Java 7 and 8) to the classpath. Connect with jdbc:oracle:thin:@//<db-host>:1521/<service-name>, or with jdbc:oracle:thin:@MYDB and -Doracle.net.tns_admin=$TNS_ADMIN.
• OCI and OCCI (C, C++, python-oracledb thick mode, PHP OCI8, Perl DBD::Oracle): set ORACLE_HOME and LD_LIBRARY_PATH=$ORACLE_HOME/lib for the application, as the wrappers do. Do not add the directory to the system library path.
• ODBC: register $ORACLE_HOME/lib/libsqora.so.12.1 as the driver in your unixODBC odbcinst.ini. Install unixODBC with sudo dnf install unixODBC.

This image ships the 12.1.0.2.0 base release. Under Oracle's Lifetime Support Policy, Oracle Database 12c Release 1 is past Premier and Extended Support. It is in Sustaining Support only, with no new Oracle patches, so check what Oracle still provides for it under your support contract.

SecureAnyCloud does not apply or redistribute Oracle patches. They are available to customers with an Oracle support contract through My Oracle Support. Apply the current client patches with your own Oracle support entitlement before you run the client in production. These resources help:

• Oracle's Critical Patch Update advisories, which list the security fixes in each quarterly update: https://www.oracle.com/security-alerts/
• The Oracle Database 12c Release 1 documentation, including patching and upgrading: https://docs.oracle.com/database/121/

Oracle's relink, which Oracle patches run, needs the C and C++ compilers and make, which the image does not ship. Install them first with sudo dnf install gcc gcc-c++ make, from the Oracle Linux 8 repositories. With them, the install-time link and relink all ran cleanly when SecureAnyCloud tested this release on Oracle Linux 8. Afterwards, you can remove them with sudo dnf remove gcc gcc-c++ make.

The Oracle home includes Oracle's own Java runtime (Java 6 update 75, from the 12.1 media) and Perl 5.14 ($ORACLE_HOME/jdk and $ORACLE_HOME/perl), which the Oracle installer and tools use. Oracle's patches update them, not dnf. Use your own current Java runtime for your applications rather than the Oracle home's.

The Oracle Linux packages update themselves: dnf-automatic applies Oracle Linux security errata every day. Check it and the pending updates with:

grep -E '^(upgrade_type|apply_updates)' /etc/dnf/automatic.conf systemctl is-enabled dnf-automatic.timer

upgrade_type = security apply_updates = yes enabled

To apply every available update now, run sudo dnf upgrade. Reboot if a new kernel was installed.

sudo ss -tlnp sudo firewall-cmd --list-services getenforce
sudo sshd -T | grep -E '^(passwordauthentication|permitrootlogin|x11forwarding|pubkeyauthentication) '

State Recv-Q Send-Q Local Address:Port Peer Address:PortProcess LISTEN 0 128 0.0.0.0:22 0.0.0.0:* users:(("sshd",pid=966,fd=3)) LISTEN 0 128 [::]:22 [::]:* users:(("sshd",pid=966,fd=4)) dhcpv6-client ssh Enforcing permitrootlogin no pubkeyauthentication yes passwordauthentication no x11forwarding no

• Only SSH listens. The image never needs an inbound port beyond 22, so keep port 1521 closed on this instance.
• The SSH settings live in /etc/ssh/sshd_config.d/00-sac.conf, which sshd_config reads first. Your EC2 key pair is the only way in. Root login and passwords are refused.
• SELinux is enforcing, and the host firewall (firewalld) allows SSH only, alongside your security group.
• The instance metadata service accepts IMDSv2 requests only (the AMI requires a session token).