Veritas File System 5.1 SP1 Administrator"s Guide (5900-1499, April 2011)

The following example performs default reclamation of free storage to the Thin

Storage LUN on a VxFS file system mounted at /mnt1:

# fsadm -R /mnt1

The following example performs aggressive reclamation of free storage to the

Thin Storage LUN on a VxFS file system mounted at /mnt1:

# fsadm -R -o aggressive /mnt1

After performing the reclaim operation, you can verify that the storage was

reclaimed using the vxdisk -o thin list command.

Veritas File System also supports reclamation of a portion of the file system using

the vxfs_ts_reclaim() API.

See the Veritas File System Programmer's Reference Guide.

Note: Thin Reclamation is a slow process and may take several hours to complete,

depending on the file system size. Thin Reclamation is not guaranteed to reclaim

100% of the free space.

You can track the progress of the Thin Reclamation process by using the vxtask

list command when using the Veritas Volume Manager (VxVM) command vxdisk

reclaim.

See the vxtask(1M) and vxdisk(1M) manual pages.

You can administer Thin Reclamation using VxVM commands.

See the Veritas Volume Manager Administrator's Guide.

Tuning I/O

The performance of a file system can be enhanced by a suitable choice of I/O sizes

and proper alignment of the I/O requests based on the requirements of the

underlying special device. VxFS provides tools to tune the file systems.

Note: The following tunables and the techniques work on a per file system basis.

Use them judiciously based on the underlying device properties and characteristics

of the applications that use the file system.

VxFS performance: creating, mounting, and tuning file systems

Tuning I/O