ptx/CLUSTERS V2.3.1 Release Notes


Introduction

These release notes support ptx®/CLUSTERS V2.3.1. Read this document before you install or run this release of ptx/CLUSTERS.


Product Compatibility

This version of ptx/CLUSTERS can be used with the following products:

For product compatibility information on products such as ptx/LAN and ptx/TCP/IP, consult the DYNIX/ptx and Layered Products Software Installation Release Notes.


Supported Cluster Configurations

This release of ptx/CLUSTERS supports 2-, 3-, and 4-node NUMA system clusters with Direct-Connect interconnects.

This release of ptx/CLUSTERS does not support the use of Fibre Channel Arbitrated Loop on NUMA systems.


What Is New In This Release

This release of ptx/CLUSTERS includes the following:


Clusterwide devbuild and devdestroy Commands

This release of ptx/CLUSTERS supports clusterwide execution of the devbuild and devdestroy commands for building and destroying devices in DYNIX/ptx. In previous releases of ptx/CLUSTERS, any devbuild or devdestroy operation had to be executed from every cluster node. Now, the devbuild or devdestroy operations on shared devices need only be executed from any one node of the cluster to affect other active nodes of the cluster.


Disk Labels and Master IDs

In DYNIX/ptx V4.6.x, the root and primary swap partitions can be located on shareable disks attached to the Fibre Channel. The system must be booted on V4.6.x before installing the root filesystem on a shareable disk or moving the root filesystem to a shareable disk. To support the ability to place the root and primary swap partitions on a Fibre Channel device, disk labels and a Master ID are now required.


Disk Labels

Disk labels are now used to specify whether disks are owned by a node or a cluster. The operating system uses these labels to control access to shareable disks (that is, disks that can be potentially accessed from multiple nodes in a cluster). In DYNIX/ptx V4.6.x, disks without disk labels will not be allowed to be opened.

The disks containing the root and primary swap partitions must be node-owned. These disks are labeled automatically when you install DYNIX/ptx V4.6.x.

A new command, diskown, is available for assigning labels to disks. This command can also be used to modify or delete a label, or to display disk label information.

You can also specify disk label information in the /etc/devlabel file. This file is read when the system is booted to multiuser mode and the appropriate labels are assigned to the disks specified in the file. We recommend that you create this file during the V4.6 installation so that all disks will be labeled appropriately.

In clustered systems, information in the /etc/devlabel file is used to write labels when you run the /etc/rolling_upgrade_complete script on each cluster node. For more information about assigning disk labels, installing DYNIX/ptx V4.6.x and ptx/CLUSTERS V2.3.x, and performing a rolling upgrade, see the DYNIX/ptx V4.6.1 and Layered Products Software Installation Release Notes and the Clusters OS and Console Rolling Upgrade to DYNIX/ptx V4.6.1 Release Notes.


Master ID

A Master ID is now required. On a single-node system, this ID can be the same as the Node ID. Each node on a clustered system must have the same Master ID, which can be the Node ID of one of the nodes in the cluster. The Master ID should be set from the VCS console after downloading the console software. (If you do not set the Master ID, the system will stop at the stand-alone kernel when it is booted.) Instructions for setting the Master ID through the VCS console are available in the DYNIX/ptx V4.6.1 and Layered Products Software Installation Release Notes.


Three- and Four-Node Clusters Now Have Full ptx/SVM Support

ptx/SVM can now be used to manage shared storage on clusters containing more than 2 nodes. If you previously disabled ptx/SVM sharing on the third or fourth nodes in a cluster, you can enable sharing on them if you wish to use ptx/SVM to manage shared storage. See the section entitled "Re-enable ptx/SVM Sharing on Cluster Nodes" later in these release notes for more information.


Install ptx/CLUSTERS

IBM authorizes only IBM personnel to perform initial cluster installations and to upgrade NUMA system clusters. IBM Customer Support or Professional Services personnel who install new clusters or update NUMA system clusters should follow the procedures in the ptx/CLUSTERS V2.x Installer's Guide and in the DYNIX/ptx V4.6.1 and Layered Products Software Installation Release Notes for installation and configuration.


Re-enable ptx/SVM Sharing on Cluster Nodes

In previous releases of ptx/CLUSTERS and ptx/SVM, ptx/SVM could not be used to manage shared storage in 3- and 4-node clusters. If you have a 3- or 4-node cluster and wish to enable ptx/SVM sharing on those nodes now that ptx/SVM sharing is available you will need to shut all cluster nodes down at the same time, install DYNIX/ptx V4.6, ptx/CLUSTERS V2.3, ptx/SVM V2.3 and other layered software on each node, and then reboot each node. If you upgrade and reboot only one node at a time and had previously disabled ptx/SVM sharing in pre-DYNIX/ptx V4.6 nodes, then the DYNIX/ptx V4.6 and pre-DYNIX/ptx V4.6 nodes will not match and the cluster will not form.


Changing Cluster Node ID

Normally, when changing a node ID in a cluster, you need to reboot only the node whose ID you are changing. However, because of a defect in the software (problem report 235185), after changing the ID of one node or more nodes, you need to reboot all nodes.

To change the node ID, follow these steps:

  1. Issue the clustadm -P nodeid=value command, where value is the new node ID (an integer between 0 and 7, inclusive). Issue this command on each node whose ID you wish to change.

  2. Shut down all cluster nodes. The recommended procedure is to first bring all the nodes to run-level 1, and then bring them to the firmware level.

  3. Start the cluster nodes back up.

Failure to follow this procedure can cause the same node to appear multiple times in clustadm output and may cause the Lock Manager to hang.


Shared Disk Groups Across Cluster Nodes

DYNIX/ptx V4.6.x and later no longer use the /etc/devtab file to store information that devbuild uses to build virtual devices on disks. Instead, the information is stored in the device naming database; the CMPT virtual device is obsolete. In ptx/CLUSTERS V2.3.x and later and ptx/SVM V2.3.x and later, you need only build the VTOC driver for a disk on one node; the naming database will propagate the information to the remaining nodes and the ptx/SVM shared disk groups will match across the cluster.


Forced Node Shutdown of a Cluster Node

There are several situations in which it is necessary for the Integrity Manager to reboot a cluster member node. In these situations, the node has become unable to safely resume access to shared storage. The Integrity Manager invokes the kernel panic mechanism to prevent any further user-level activity that might require access to shared storage and to bring the node most rapidly back into cluster membership. The panic messages used, and their causes, are the following:


Guidelines for Removing a Node from a Cluster

To remove a node from a cluster, follow these steps:

  1. Shut down the node you wish to disconnect from the cluster and power it off.

  2. Disconnect all shared storage from the node to be removed from the cluster.

  3. Disconnect the node from the CCI networks.

  4. Boot the node you wish to remove from the cluster. Go to single-user mode, either with the bootflags or by entering s at the Waiting for cluster membership, enter 's' to go to single-user mode prompt.

  5. Through ptx/ADMIN, deinstall the ptx/CLUSTERS software. For information on how to deinstall software, see the DYNIX/ptx and Layered Products Software Installation Release Notes.


    ATTENTION

    To avoid destroying or corrupting data, do not remove the ptx/CLUSTERS software before detaching the node from all shared storage.


  6. On the remaining nodes, reset the number of expected votes to equal the number of remaining nodes plus the quorum disk, if one is configured.


Product Documentation

The following documentation is available on the online documentation CD and at http://webdocs.numaq.ibm.com/:

ptx/CLUSTERS Administration Guide
ptx/CLUSTERS Installer's Guide (IBM Customer Support group only)


Problem Reports

This section lists the following problem report summaries:

The numbers in parentheses identify the problems in the problem-tracking system.


Fixed Problems in ptx/CLUSTERS V2.3.1

The following problems have been fixed in ptx/CLUSTERS V2.3.1.


Fixed Problems in ptx/CLUSTERS V2.3.0

The following problems were fixed in ptx/CLUSTERS V2.3.0.


Open Problems in ptx/CLUSTERS V2.3.1

This section lists open problems in this release of ptx/CLUSTERS. The numbers in parentheses identify the problems in the IBM problem-tracking system.


Installation of ptx/CLUSTERS Removes ptx/CTC Menu Entries (237168)

ptx/CTC menus in ptx/ADMIN are removed if an updated version of ptx/CLUSTERS is installed and ptx/CTC is not reinstalled.

Workaround. Always install ptx/CLUSTERS and ptx/CTC together. If you have already installed ptx/CLUSTERS, install ptx/CTC from the CD-ROM so that the menus will reappear.


clustadm -C and clustadm -D Hang When Node Has Lost Quorum (241693)

The clustadm -C (configure quorum disk) and clustadm -D (deconfigure quorum disk) will hang when the node has lost quorum. The commands cannot be suspended or interrupted.

Workaround. Boot another node to restore quorum or reboot the node and only make quorum disk configuration changes while the node has quorum.


devdestroy Fails for Device That Hosted the Quorum Disk (243003)

When a quorum disk is configured, the VTOC, if it is not already in place, is built for the device on remote nodes from the kernel. However, this does not update the list of built devices at the user level.

Workaround. Execute the devbuild command on the node where the devdestroy is failing. Doing so will update the list of built devices. Then do the devdestroy.


A Node May Be Down or Powered Off and Other Nodes May Report It Is Still a Cluster Member (246261)

When a cluster member node is shut down, the other member nodes will continue to report that it is a member until VSYNC has completed its membership view change protocol. This protocol includes a delay known as "I/O drain time," during which the view change waits for completion of any I/O requests initiated before the node was shut down to either complete or fail. Thus it is possible, if this I/O drain time is long enough, for a node to be completely shut down and even powered off while clustadm on other nodes continues to report that the node is still a cluster member. clustadm will report that all links to the shut down node are DOWN during this delay in the membership view change protocol. This is the indication that the protocol is underway and should complete shortly.

Workaround. This is a transient problem which will correct itself after the I/O drain time delay has passed.


ptx/SDI Must Be Installed on All Nodes or No Nodes (250365)

If one cluster node is running ptx/SDI and has a ptx/SDI device, then another node that attempts to join the cluster must also have ptx/SDI installed. Likewise, if an existing cluster node does not have ptx/SDI installed, then another node that attempts to join the cluster must also not have ptx/SDI installed. Otherwise, when the nodes attempt to synchronize their naming databases, the following error will occur:

devctl: Internal error 3 during NDB merge operation: Invalid argument
devctl: unable to synchronize NDB: Invalid argument

Workaround. Ensure that ptx/SDI is either installed on all cluster nodes or on none.


The clustadm Command Displays "qdisk path" Instead of "qdisk name" (254642)

When a cluster with a quorum disk is booted with the -I -n <ndb.new> option, the clustadm command displays the qdisk path in place of the qdisk name.

Workaround. When a cluster node is booted with the -I -n<ndb.new> option, it is possible for the clustadm command to display the quorum disk as /dev/rdsk/clust_qdisk. To recover from this state, take all nodes to multiuser mode and ensure that device naming has completed on all the nodes in the cluster. Then try deconfiguring the quorum disk (using clustadm -D) and reconfiguring a quorum disk (using clustadm -C <qdisk>).