User Guide

Chapter 6: Technology Background

address blocks or sectors. This limitation does not apply to Windows XP (64-bit),

2003 Server, Vista, and Linux OSes with the 2.6 kernel.

For Windows 2000 and Windows XP (32-bit), multiply the number of blocks by

the sector size to find the capacity of a logical drive:

4,000,000,000 blocks x 512 bytes per sector = 2,048,000,000,000 bytes

of data for a 2TB drive.

Note that you cannot change the size of the sectors nor can you increase the

number of address blocks above 4 billion.

As a result, there are range limits imposed upon logical drive migration as shown

in the table above. For example:

• You can migrate a 2.5 TB logical drive up to 4 TB

• You can only migrate a 1.9 TB logical drive up to 2 TB

See the chart below.

You can direct WebPAM to migrate a logical drive beyond the maximum size.

However, when migration is finished, your logical drive will be the maximum size

listed in the table.

If you require a logical drive larger than the maximum migration size:

1. Backup the data from the current logical drive.

2. Delete the current logical drive.

3. Create a new logical drive with the desired capacity.

4. Restore the data to the new logical drive.

Current LD Size

Maximum LD

Migration Size

Sector Size

8 to 16 TB 16 TB 4096 bytes

4 to 8 TB 8 TB 2048 bytes

2 to 4 TB 4 TB 1024 bytes

0 to 2 TB 2 TB 512 bytes