What's New in File Systems?

This section describes new file system features.

The /var/run File System

A new TMPFS-mounted file system, /var/run, is the repository for temporary system files that are not needed across system reboots in this Solaris release and future releases. The /tmp directory continues to be repository for non-system temporary files.

Because /var/run is mounted as a memory-based file system rather than a disk-based file system, updates to this directory do not cause unnecessary disk traffic that would interfere with systems running power management software.

The /var/run directory requires no administration. You may notice that it is not unmounted with the umount -a or the umountall command.

For security reasons, /var/run is owned by root.

Mount Table Changes (/etc/mnttab)

In previous Solaris releases, /etc/mnttab was a text-based file that stored information about mounted file systems. The downside of being a file was that it could get out of sync with the actual state of mounted file systems.

Now the /etc/mnttab file is a MNTFS file system that provides read-only information directly from the kernel about mounted file systems for the local system.

Note the following mnttab behavior changes:

• Programs or scripts attempting to write to /etc/mnttab will fail.

• The mount -m option for faking mnttab entries no longer works.

No administration is required for the /etc/mnttab mount table.

See mnttab(4) for more information.