4.10 Log on to the zCX instance This section describes how to log on to the zCX instance where you can use ssh. Here is the  procedure that we followed: 1. Log on to the USS environment of z/OS using the RACF administrator user ID that you  created in 4.2.5, “Create RACF user IDs” on page 52. We logged on to USS by using  ZCXADM1. 2. Enter this command to log on to the zCXinstance:  ssh admin@sc74cn01.pbm.ihost.com -p 8022 For this first logon, you get the response shown in Example 4-20. Example 4-20 Response connecting to zCX instance the first time via ssh The authenticity of host '[sc74cn01.pbm.ihost.com]:8022 ([129.40.23.68]:8022)'  can't be established. ECDSA key fingerprint is SHA256:IA5Sw4oNK7wODhFGkH4ayyJNvT73m1uvQprHjqOC41M. Are you sure you want to continue connecting (yes/no)?  You can disregard the warning message about the authenticity of the host, as this is  expected ssh behavior. Respond ‘yes’ to the prompt, and press  Enter . The logon should  be complete and shows output similar to that in Example 4-21. Example 4-21 Messages showing successful logon to the zCX instance FOTS2274 Warning: Permanently added  '[sc74cn01.pbm.ihost.com]:8022,[129.40.23.68]:8022' (ECDSA) to the list of known  hosts. Welcome to the IBM z/OS Container Extensions (IBM zCX) shell that provides access  to Docker commands. For more information on how to use this shell to execute Docker commands refer to  "IBM z/OS Container Extensions Guide". Sudo only permits specific User Management functions. See additional  documentation for details. admin@d377e12aa94b:~$ id uid=1001(admin) gid=1001(admin) groups=1001(admin),27(sudo),109(docker) 3. Issue the id command to confirm that the user ID we have logged in to the zCX instance  as is called  admin . This was the value that we set for the property  ZCX_DOCKER_ADMIN  as described in 4.7.1, “Customizing the properties file” on page 60. Now that you are logged in to the zCX instance, you can follow the steps in Chapter 5., “Your  first running Docker container in zCX” on page 97 to create and run your first Docker  containers. 4.11 Reconfiguring a zCX instance In this section, we describe how to reconfigure an existing zCX instance to change settings  such as number of virtual CPs and memory size. Chapter 4. Provisioning and managing your first z/OS Container  79