If you are using standard Windows 2003, then you can use the "DiskPart.exe" utility from the Microsoft resource kit.
Use the "rescan" command at a command prompt with diskpart.exe to allow the OS to see the additional free space for the drive. Then use the "extend size = xxxx" command to extend the disk.
Dig Deeper on SAN technology and arrays
Related Q&A from Christopher Poelker
SAN expert Chris Poelker compares connecting a SAN with wavelength cabling and dark fiber and discusses the pros and cons of each. Continue Reading
Storage expert Chris Poelker outlines WWN basics in order to answer the question: "Why do HBAs in a SAN have same base?" Continue Reading
Storage expert Chris Poelker discusses SATA/SCSI compatibility issues in this expert advice article. Continue Reading