DB2 V9.5 的db2diag.log文件保存地址修改
网上找了一段时间，按老方法一直没有找到，最后在这里发现了
http://www-01.ibm.com/support/docview.wss?uid=swg21380494
In DB2 V9.5, the location of db2diag.log is changed:

For Windows XP and Windows 2003 operating systems:
C:\Documents and Settings\All Users\Application Data\IBM\DB2\<DB2 copy name>\DB2

For Windows Vista and later operating systems:
C:\ProgramData\IBM\DB2\<db2 copy name>\DB2


NOTE:注意
* Application Data is a hidden folder.（是个隐藏文件夹）

* The default location can be modified by updating the 'diagpath' dbm cfg parameter to a desired location.