Note: In this release, relocation is disabled by default and recovery is supported only when using standby nodes.
A standby node is a metadata server-capable administration node that is configured as a potential metadata server for a given filesystem, but does not currently run any applications that will use that filesystem. To use recovery, you must not run any applications on any of the potential metadata servers for a given filesystem; after the active metadata server has been chosen by the system, you can then run applications that use the filesystem on the active metadata server and client-only nodes. Relocation and recovery are fully implemented, but the number of associated problems prevents full support of these features in the current release. Although data integrity is not compromised, cluster node panics or hangs are likely to occur. Relocation and recovery will be fully supported in a future release when these issues are resolved. |
This update contains the following:
IRIX nodes may now be CXFS client-only nodes, meaning that they run a minimal implementation of the CXFS and cluster services, and do not contain a copy of the CXFS cluster database. Client-only nodes are installed with the cxfs_client software product.
This change also introduces the term CXFS administration node, which is a node that is installed with the cluster_admin software product, allowing the node to perform cluster administration tasks and contain a copy of the cluster database. Nodes that you want to run as metadata servers must be installed as CXFS server-capable administration nodes; SGI recommends that all other nodes be installed as client-only nodes.
When you define a node, you no longer need to specify the node weight. This has been replaced by the Node Function field, allowing you to choose Server-capable Admin, Client Admin, or Client-Only. (For Solaris and Windows nodes, Client-Only is automatically selected for you.) Similar fields are provided for the cmgr(1M) command.
See the following:
When upgrading to 6.5.18f, already existing IRIX nodes will by default be assigned as Server-capable Admin if they had a weight of 1.
This version also clarifies the terms used for membership: CXFS kernel membership and cluster database membership. See “Terminology” in Chapter 1.
New system-tunable parameters:
cxfs_relocation_ok lets you enable or disable the relocation feature; relocation is disabled by default in this release, and SGI recommends that you do not enable it.
cxfsd_min and cxfsd_max let you specify the minimum and maximum number of cxfsd threads to run per CXFS filesystem.
New commands:
cxfs_info(1M) provides status information about the cluster, nodes, and filesystems and is run from a client-only node. See “Check Cluster/Node/Filesystem Status with cxfs_info” in Chapter 9.
cxfsdump(1M) gathers CXFS configuration information. See “Gather Cluster Configuration with cxfsdump” in Chapter 10.
A CXFS cluster is supported with as many as 32 nodes. As many as 16 of those nodes can be CXFS administration nodes and all other nodes can be client-only nodes. You can choose to define a node as a CXFS client administration node, however, SGI strongly recommends that only potential metadata servers be configured as CXFS server-capable administration nodes and that there be an odd number of server-capable nodes for quorum calculation purposes.
The graphical user interfaces for XVM and CXFS have been combined into one; see “GUI Overview” in Chapter 4. This guide provides an overview of the XVM-specific tasks provided by the GUI; for details about these tasks, see the XVM Volume Manager Administrator's Guide.
The following filesystem tasks are now provided in the GUI and documented in this guide:
Tips about using CXFS and Trusted IRIX; see Chapter 8, “Trusted IRIX and CXFS”.
Support for Microsoft Windows 2000 systems as client-only nodes. (This guide uses Windows to refer to both Microsoft Windows NT and Microsoft Windows 2000 nodes when the information applies equally to both. Information that applies to only one of these types of nodes is identified.)