Administrator's Guide

Technical Overview
VxFS Functionality on Cluster File Systems
Chapter 1
10
See the HP Serviceguard Storage Management Suite Release Notes in the High
Availability section at http://www.docs.hp.com for more information on bundle features
and options.
Unsupported Features
Functionality that is documented as unsupported may not be expressly prevented from
operating on CFS, but the actual behavior is indeterminate. HP does not advise using
unsupported functionality on CFS, or to alternately mount file systems with
unsupported features as local and cluster mounts.
Disk Layout
Versions
CFS supports only disk layout Version 6 and Version 7. Cluster
mounted file systems can be upgraded. A local mounted file system
can be upgraded, unmounted, and mounted again, as part of a cluster.
Use the fstyp -v special_device command to ascertain the disk
layout version of a VxFS file system. Use the vxupgrade command to
update the disk layout version.
Locking Advisory file and record locking are supported on CFS. For the
F_GETLK command, if there is a process holding a conflicting lock, the
l_pid field returns the process ID of the process holding the
conflicting lock. The nodeid-to-node name translation can be done by
examining the /etc/llthosts file or with the fsclustadm
command. Mandatory locking and deadlock detection supported by
traditional fcntl locks are not supported on CFS.
See the fcntl(2) manual page for more information.
Multiple
Transaction
Servers
With this feature, CFS moves from a primary/secondary architecture,
where only one node in the cluster processes metadata operations
(file creation, deletion, growth, etc.) to a symmetrical architecture,
where all nodes in the cluster can simultaneously process metadata
operations. This allows CFS to handle significantly higher metadata
loads.
Table 1-1 CFS Supported Features (Continued)
Features and Commands Supported on CFS
Table 1-2 CFS Unsupported Features
Features and Commands Not Supported on CFS
qlog Quick log is not supported on CFS.
Swap Files Swap files are not supported on CFS.
The mknod
command
You cannot use the mknod command to create devices 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.