HP-UX System Administrator's Guide: Routine Management Tasks

VxFS file systems: Unlike HFS file systems, VxFS file systems can be switched between
largefiles and nolargefiles without unmounting (and without requiring an
fsck operation to verify file system state). However, as with HFS file systems, you
must remove any large files (files with size greater than 2GB) from the file system before
a switch between largefiles to nolargefiles will succeed.
NOTE: largefiles and nolargefiles are mount options to file systems. If you
manually switch a file system between one mode and another, you might need to edit
the corresponding entry in the file /etc/fstab so that future mounts and boots will
mount the file system using the proper mode.
Command Support for Large Files
All of the file system administration commands, as well as all file system user commands,
for HFS and VxFS support large files (greater than 2 GB in size).
If a command that does not support large files encounters a large file, the command
will return an [EOVERFLOW] error and print a message like the following:
Value too large to be stored in data type
Repairing a Large-Files File System with fsck
The fsck(1M) command repairs damaged file systems. Typically, large files should not
appear in a no-large-files file system. There are two ways fsck recovers from this
situation if a large file does appear.
In the first scenario, you use fsck in the interactive mode. fsck finds a large file on
a no-large-files file system, marks the file system dirty and stops. You can then correct
the situation using the fsadmcommand with the -o largefiles option. The fsck
command repairs the file system, which you are then able to mount. This scenario
would preserve the large file, if fsck did not find it corrupt in any other way.
In the second scenario, using non-interactive mode, fsck purges the large file on a
no-large-files file system. fsck assumes the superblock to be accurate based on its
accuracy checks since the probability of a superblock being corrupt is insignificant
when compared to the instance of a large file manifesting in a no-large-files file system.
Consequently, fsck will remove the large file from a file system it believes should not
contain large files.
The mount Command and Large-Files File Systems
The mount command supports large-files file systems and provides you with a method
of ensuring that no large-files file systems are mounted on the system.
The mount command uses the same two options as the mkfs, newfs, and fsadm
commands (largefilesand nolargefiles). mount will not mount a large-files file
system if the -o nolargefiles option is specified. Conversely, the mount command
will not mount a no-large-files file system if the -o largefiles option is specified.
118 Managing Systems