Different hardware vendors have different track sizes and may recommend that a volume start at a specific disk offset for optimal performance.  From Storage Foundation for Windows (SFW) 5.0, this disk offset can automatically be configured when a new volume is created.

Example:

The default starting sector for disks that have more than 63 sectors per track is the 64th sector, but the default starting sector of the SFW public region is the 63rd sector.  As Windows Server reads 4KB per sector (assuming 64 sectors per track) this means that one in eight blocks of data will span two tracks.  This causes more work to be have to done at the disk level per read/write.

To enable or disable track alignment support, follow these steps:

1. From VEA (Veritas Enterprise Administrator), click Control Panel.
2. Double-click Track Alignment Settings.
3. Click Enable track alignment support. Each model may be enabled or disabled individually.

From here it is also possible to enable/disable track alignment for specific arrays and to check the default offset per array.

 
Figure 1 - Track Alignment Settings

For SFW 4.3 and earlier:

A small, unformatted, "buffer" volume can be created at the beginning of the disk. This forces the next volume that is created to start at a specific disk offset.  If the volume spans multiple disks on the same array, this buffer volume will need to be created on all disks.

Use this formula to calculate the size of the "buffer" volume (in sectors):

(Vendor Recommended Offset) - 63 = (Size of "Buffer" Volume in Sectors)

Note: The default disk offset for the first volume on a disk is 63.

For example:

The offset of a volume can be verified by following these steps:

1. From VEA, expand Volumes.
2. Click on a volume to highlight it.
3. Click Subdisks (Figure 2).
4. The disk offset of the selected volume is found under Disk Offset.

Figure 2