Table 2 CFS Unsupported Features (continued)
Features and Commands Not Supported on CFS
Cache Advisories | Cache advisories are set with the mount command on individual file systems, but are not |
| propagated to other nodes of a cluster. |
Cached Quick I/O | This Quick I/O for Databases feature that caches data in the file system cache is not supported |
| on CFS. |
Commands that | File access times may appear different across nodes because the atime file attribute is not |
Depend on File Access | closely synchronized in a cluster file system. Utilities that depend on checking access times |
Times | may not function reliably. |
Cluster Communication
Group Membership Atomic Broadcast (GAB) and Low Latency Transport (LLT) are protocols implemented directly on ethernet data links. They run on redundant data links that connect the nodes in a cluster. Serviceguard and CFS are in most respects, two separate clusters. GAB provides membership and messaging for the clusters and their applications. GAB membership also provides orderly startup and shutdown of clusters. LLT is the cluster communication transport. The /etc/ gabtab file is used to configure GAB and the /etc/llttab and /etc/llthosts files are used to configure LLT. Serviceguard cmapplyconf creates these configuration files each time the CFS package is started and modifies them whenever you apply changes to the Serviceguard cluster configuration - this keeps the Serviceguard cluster synchronized with the CFS cluster.
Any attempt to directly modify /etc/gabtab, /etc/llttab, or /etc/llthosts will be overwritten by cmapplyconf(or cmdeleteconf).
Membership Ports
Each component in a CFS registers with a GAB membership port. The port membership identifies nodes that have formed a cluster for the individual components. Examples of port memberships include:
port a | heartbeat membership |
port f | Cluster File system membership |
port u | Temporarily used by CVM |
port v | Cluster Volume Manager membership |
port w | Cluster Volume Manager daemons on different nodes communicate with one another |
using this port.
Port memberships are configured automatically and cannot be changed. To display port memberships, enter the gabconfig
CFS differences in a Serviceguard Storage Management Suite environment
This section includes information that is specific to CFS in a Serviceguard Storage Management
Suite environment and is either not included in the Veritas Storage Foundation™ 5.1 SP1 Cluster File System Administrator's Guide, or is different than what is published in the Veritas Storage Foundation™ 5.1 SP1 Cluster File System Administrator's Guide.
File system size limits
For maximum supported file system sizes, see Supported File and File System Sizes for HFS and JFS available at: http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01915880/ c01915880.pdf
6Overview