HP UX Serviceguard Storage Management Software manual CFS Unsupported Features

Technical Overview

VxFS Functionality on Cluster File Systems

Table 1-1	CFS Supported Features (Continued)
		Features and Commands Supported on CFS
	Disk Layout	CFS supports only disk layout Version 6 and Version 7. Cluster
	Versions	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	With this feature, CFS moves from a primary/secondary architecture,
	Transaction	where only one node in the cluster processes metadata operations
	Servers	(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.
	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.

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		You cannot use the mknod command to create devices on CFS.
	command
	Cache		Cache advisories are set with the mount command on individual
	Advisories		file systems, but are not propagated to other nodes of a cluster.
	Cached Quick		This Quick I/O for Databases feature that caches data in the file
	I/O		system cache is not supported on CFS.

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