Complete the cluster configuration checklist to ensure that your environment is prepared properly before you begin to configure your cluster.
| TCP/IP requirements | |
|---|---|
| __ | Start TCP/IP on every node you plan to include in the cluster using the Start TCP/IP (STRTCP) Command. |
| __ | Configure the TCP loopback address (127.0.0.1) and verify that it shows a status of Active. Verify using the Work with TCP/IP Network Status (WRKTCPSTS) Command on every node in the cluster. |
| __ | Verify that the IP addresses used for clustering to a given node must show a status of Active using the Work with TCP/IP Network Status (WRKTCPSTS) Command on the subject node. |
| __ |  Verify that INETD is active on all nodes in the cluster
by using either the STRTCPSVR *INETD command or through iSeries™ Navigator
by completing the following steps:
 |
| __ |
Verify that user profile for INETD, which is specified in /QIBM/ProdData/OS400/INETD/inetd.config,
does not have more than minimal authority. The Start Cluster Node (STRCLUNOD)
command will fail, if this user profile has more than minimal authority.
By default, QUSER is specified as the user profile for INETD. |
| __ |
Verify every IP address in the cluster can route to and send UDP datagrams
to every other IP address in the cluster. Use the PING command specifying
a local IP address and the TRACEROUTE command specifying UDP messages. |
| __ | Verify that ports 5550 and 5551 are not being used by other applications. These ports are reserved for IBM® clustering. Port usage can be viewed using the Work with TCP/IP Network Status (WRKTCPSTS) command. Port 5550 will be opened and in a 'Listen' state by clustering once INETD is started. |
If you plan to use switchable devices in your cluster, the following requirements must be satisfied:
| Resilient device requirements | |
|---|---|
| __ | Verify that Option 41 (HA Switchable Resources) is installed and a valid license key exists on all cluster nodes that will be in the device domain. Note that any use of the iSeries Navigator cluster management interface requires this option. |
| __ | In order to access disk management functions in iSeries Navigator, configure the service tools server (STS) with DST access and user profiles. See Set up communication for details. |
| __ | If you are switching resilient devices between logical partitions on
a system, and you are using something other than the HMC to manage your logical
partitions, enable Virtual OptiConnect for the partitions. This is done at
dedicated service tools (DST) signon. See Virtual
OptiConnect for details. If you are using the Hardware Management Console to manage your partitions, change your partition profile properties on the OptiConnect tab to enable Virtual OptiConnect for each partition in the switchable configuration. You must activate the partition profile to reflect the change. |
| __ | If a tower on an HSL OptiConnect loop is switched between two systems,
and one of the systems has logical partitions, enable HSL OptiConnect for
the partitions. If you are using something other than the HMC to manage logical
partitions, this is done at dedicated service tools (DST) signon. If you are using the Hardware Management Console to manage your partitions, change your partition profile properties on the OptiConnect tab to enable HSL OptiConnect for each partition in the switchable configuration. You must activate the partition profile to reflect the change. |
| __ | If you are switching resilient devices between logical partitions,
and you are using something other than the HMC to manage your logical partitions,
you must configure the bus to be shared between the partitions or configure
an I/O Pool. The bus must be configured the bus as "own bus shared" by one
partition, and all other partitions that will participate in the device switching
must be configured as "use bus shared." If you are using the Hardware Management
Console to manage your logical partitions, you must configure an I/O Pool that includes the
I/O processor, I/O adapter, and all attached resources to allow an independent
disk pool to be switchable between partitions. Each partition must have access
to the I/O pool. See Make
your hardware switchable for more details. |
| __ | When switching a tower on a HSL loop between two different systems, the tower must be configured as switchable. See Make your hardware switchable for details. |
| __ | When a tower is added to an existing HSL loop, restart all servers on that same loop. |
| __ | The maximum transmission unit (MTU) for your communication paths must be greater than the cluster communications tuneable parameter, message fragment size. MTU for a cluster IP address can be verified using the Work with TCP/IP Network Status (WRKTCPSTS) command on the subject node. The MTU must also be verified at each step along the entire communications path. It may be easier to lower the message fragment size parameter once the cluster is created than raise the MTU for the communications path. See Tunable cluster communications parameters for more information about message fragment size. You can use the Retrieve Cluster Resource Services Information (QcstRetrieveCRSInfo) API to view the current settings of the tuning parameters and the Change Cluster Resource Services (QcstChgClusterResourceServices) API to change the settings. |
| Security requirements | |
|---|---|
| __ | The ALWADDCLU (Allow Add to Cluster) network attribute must be appropriately set on the target node if trying to start a remote node. This should be set to *ANY or *RQSAUT depending on your environment. If set to *RQSAUT, then i5/OS™ option 34 (Digital Certificate Manager) and Cryptographic Access Provided Product must be installed. See Enable a node to be added to a cluster for details on setting the ALWADDCLU network attribute. |
| __ | Enable the status of the user profile for INETD specified
in /QIBM/ProdData/OS400/INETD/inetd.config. It must not have *SECADM or *ALLOBJ
special authorities. By default, QUSER is specified as the user profile for
INETD. |
| __ | Verify that the user profile invoking the cluster resource services APIs exists on all cluster nodes and has *IOSYSCFG authority. |
| __ | Verify that the user profile to run the exit program
for a cluster resource group (CRG) exists on all recovery domain nodes. |
| Job considerations | |
|---|---|
| __ | Jobs can be submitted by the cluster resource services APIs to process requests. The jobs will either run under the user profile to run the exit program specified when creating the a cluster resource group, or under the user profile that requested the API (for varying on devices in resilient device CRGs only). The user must ensure that the subsystem which services the job queue associated with the user profile is configured as: *NOMAX for the number of jobs it can run from that job queue. |
| __ | Jobs will be submitted to the job queue specified by the job description which is obtained from the user profile defined for a CRG. The default job description will cause the jobs to be sent to the QBATCH job queue. Since this job queue is used for many user jobs, the exit program job may not run in a timely fashion. Users should consider a unique job description with a unique user queue. |
| __ | When exit program jobs are run, they will use routing data from the job description to choose which main storage pool and run time attributes they will use. The default values will result in jobs that are run in a pool with other batch jobs with a run priority of 50. Neither of these may produce the desired performance for exit program jobs. The subsystem initiating the exit program jobs (the same subsystem that is using the unique job queue) should assign the exit program jobs to a pool that is not used by other jobs initiated by the same subsystem or other subsystems. In addition, the exit program jobs should be assigned a run priority of 15 so that they will run before almost all other user jobs. |
| __ |
The QMLTTHDACN system value must be set to 1 or 2. |
There are several software solutions available for configuring and managing your cluster. One of these solutions is iSeries Navigator cluster management. If you choose to use iSeries Navigator, the following requirements must be satisfied:
| iSeries Navigator cluster management considerations | |
|---|---|
| __ | Option 41 (i5/OS - HA Switchable Resources) must be installed and a valid license key must exist on all cluster nodes that will be in the device domain. |
| __ | Verifty that all host servers are started using the STRHOSTSVR (Start Host Server) Command: STRHOSTSVR SERVER(*ALL) |
| __ | Verify that the Management Central server is started using the STRTCPSVR (Start TCP/IP Server) Command: STRTCPSVR SERVER(*MGTC) |