9    Cluster Installation and Administration

This chapter provides an overview of cluster installation and administration.

9.1    Installation

Previous versions of TruCluster supported three installation types: full installation, rolling upgrade, and simultaneous upgrade. The rolling upgrade and simultaneous upgrade procedures provided a way to preserve the existing cluster or ASE configuration information while installing a later version of the product.

TruCluster Server Version 5.0 and Version 5.0A support two installation types: a full installation and an upgrade procedure. Rolling upgrade is not supported for these initial releases because there are significant changes to both the base operating system and the cluster architectures. For this reason, the recommended installation path is a full installation of the base operating system followed by a full installation of the TruCluster Server.

The TruCluster Server Software Installation manual describes how to upgrade a Version 5.0 cluster to a Version 5.0A cluster. That manual also provides three options for customers upgrading to Version 5.0A from TruCluster Software Version 1.5 or Version 1.6 products. Two of these upgrade options use scripts specifically designed to facilitate the migration of storage from the old cluster (rz* style device names) to the new cluster (dsk* style device names).

TruCluster Server Version 5.0A incorporates the software infrastructure required to support future rolling upgrades. Customers who install TruCluster Server Version 5.0A will be able to perform a rolling upgrade to the next TruCluster Server release. As part of preparing for rolling upgrades, TruCluster Server Version 5.0A provides a new command, clu_upgrade, which will control the rolling of a cluster to the next release. Note that this command will be of use only when you are installing the release that follows Version 5.0A. See clu_upgrade(8) for a description of the clu_upgrade command.

One major difference in installing TruCluster Server Version 5.* is that you install Tru64 UNIX on only one system in the cluster. Because CFS creates shared clusterwide file systems, once a cluster is created, additional members boot into the cluster and have access to these files. (In previous releases, you had to install the base operating system on all cluster members, and there were no clusterwide file systems.)

For TruCluster Server, the initial creation of a cluster, the adding of members, and the removing of members are accomplished through three interactive installation scripts: clu_create, clu_add_member, and clu_delete_member. The scripts provide online help and write log files to the /cluster/admin directory.

The following list outlines the steps needed to form a new TruCluster Server cluster:

1. Using the information in the TruCluster Server Hardware Configuration manual, configure the system and storage hardware and firmware.

2. Selecting AdvFS file systems, install Tru64 UNIX on a private disk on the system that will become the first cluster member.

3. Configure the Tru64 UNIX system, including network and time services. Load and configure the applications you plan to use in the cluster.

4. Load the TruCluster Server license and software.

   Note

   Each cluster member must have both a Tru64 UNIX license and a TruCluster Server license.

5. Run the clu_create command to create the boot disk for the first cluster member, and to create and populate the clusterwide root (/), /usr, and /var AdvFS file systems.

6. Halt the Tru64 UNIX system and boot the disk containing the first member's cluster boot partition. As the system boots, it forms a single-member cluster and mounts the clusterwide root (/), /usr, and /var file systems.

7. Log in to the single-member cluster and run the clu_add_member command to add members to the cluster.

See the TruCluster Server Software Installation manual for more information on installing TruCluster Server.

9.2    Administration

Having a clusterwide file namespace greatly simplifies cluster management. A cluster has just one copy of most system configuration files. For example, a cluster is managed as a single security domain through one /etc/group file and one /etc/passwd file.

User access to files is independent of which node a user is logged in on, and which node is serving the file. File permissions and access control lists (ACLs) are uniform across the cluster.

Audit logs are kept in a common location; each member's host name is appended to its log files to avoid confusion when tracking audit events.

In most cases, the fact that you are administering a cluster rather than a single system becomes apparent because of the occasional need to manage one of the following aspects of a TruCluster Server environment. Each item is followed by one or more of the cluster-specific commands used to manage or monitor it. With the exception of the installation scripts, you can use the SysMan Menu and SysMan Station GUIs to perform the related command-line functions.

• Cluster creation and configuration, which supports creating the initial cluster member, adding and deleting members, and querying the cluster configuration (clu_create, clu_add_member, clu_delete_member, and clu_check_config).

• Cluster application availability (CAA), which allows you to define and manage highly available applications (caa_profile, caa_register, caa_unregister, caa_start, caa_stop, caa_relocate, and caa_stat).

• Cluster aliases, which provide a single system view from the network (cluamgr).

• Cluster quorum and votes, which determine what constitutes a valid cluster and membership in that cluster, and thereby allows access to cluster resources (clu_quorum).

• Optional load-balancing of the device request dispatcher subsystem (drdmgr).

• Optional load-balancing of CFS servers (cfsmgr).

In addition to the previous items, there are some command-level exceptions to the Single System Image (SSI) model. SSI means that, when possible, the cluster appears to the user like a single computer system. For example, when you execute the wall command, the message is sent only to users logged in on the cluster member where the command executes. To send a message to all users logged in on all cluster members, use the wall -c form of the command. The same logic applies to the shutdown command; you can shut down an individual member or the entire cluster.

See the TruCluster Server Cluster Administration manual for more information on configuring and managing a TruCluster Server cluster.