We suggest that you use DB2 on a 64-bit operating system whenever possible, since the limits discussed in the previous section do not exist. In addition, in a 64-bit environment, shared memory segments can be allocated and deallocated dynamically, making configuring and tuning of your DB2 server more dynamic and much easier.
DB2 currently supports the following 64-bit operating systems:
AIX
HP/UX
Linux on AMD
Linux on Intel (IPF)
Linux on Power
Solaris
Windows 2003 Advanced Server