Veritas File System 5.0 Release Notes, HP-UX 11i v3, First Edition, May 2008

• Large File Systems and Large File Support
The HP OnlineJFS license is required to create file systems over 2 TB and under 32 TB. The
EBFS license is required to create file systems over 32 TB. The EBFS license is bundled with
HP Serviceguard Storage Management suite. Please contact the HP sales representatives for
further information about obtaining this license.
For information on supported file systems and large file support, see the Supported File and
File System Sizes for HFS and JFS whitepaper available at:
http://www.docs.hp.com
• Cross Platform Data Sharing
Cross-platform Data Sharing (CDS) allows data to be serially shared among heterogeneous
systems, where each system has direct access to the physical devices that hold the data. This
feature can be used only in conjunction with the Veritas Volume Manager. For more
information, see the Veritas Storage Foundation Cross-Platform Data Sharing Administrator’s
Guide. This feature was introduced with the VxFS 4.1 release on HP-UX 11i v3. CDS is
supported only on VxFS file systems with Disk Layout Version 6 or later.
The new VxFS commands associated with the CDS feature are:
fscdsadm : Perform online Cross-Platform Data Sharing operations on a VxFS file system.
NOTE: In VxFS 4.1, the fscdstask script was provided to perform the various VxFS CDS
administration tasks. Starting with the VxFS 5.0 release, the fscdsadm command must be
used to perform all online CDS tasks on a VxFS file system in place of the fscdstask
command. The fscdstask script is deprecated and is provided only for backward
compatibility with the previous releases. The support for the fscdstask script will be
discontinued in future VxFS releases.
fscdsconv : Make a VxFS file system suitable for migration to another target.
NOTE: To enable the CDS feature an additional license is required. The CDS feature is not
supported with Base-VxFS and HP OnlineJFS. See Table 1-3 for the products that bundle
this license.
• Concurrent I/O
Concurrent I/O (VX_CONCURRENT) allows multiple processes to read or write to the same
file without blocking other read (2) or write(2) calls. POSIX semantics requires read(2)
and write(2) calls to be serialized on a file with other read(2) and write(2) calls. With
POSIX semantics, a read(2) either reads the data before or after the write(2) occurred.
With the VX_CONCURRENT advisory set to on, the read(2) and write(2) operations are
not serialized as in the case of a character device. This advisory is generally used by
applications that require high performance for accessing data and do not perform overlapping
writes to the same file. It is the responsibility of the application or the running threads to
coordinate the write(2) activities to the same file when using Concurrent I/O.
Concurrent I/O can be enabled in two ways:
— Concurrent I/O can be set using the file descriptor and the ioctl(2) call using the
VX_SETCACHE ioctl command with the VX_CONCURRENT advisory flag. Only the
read (2) and write (2) calls occurring through this file descriptor use concurrent
I/O. The read(2) and write(2) operations occurring through other file descriptors
will still follow the POSIX semantics. See vxfsio(7) (7) manpage, for more details.
— Concurrent I/O can be enabled on all files in the file system mounted using the cio
mount option.
The read(2) and write(2) operations occurring on all the files in this particular file
system will use concurrent I/O. For more information, see mount_vxfs(1M).
New Features 9