The instance directory stores all information that pertains to a database instance. You cannot change the location of the instance directory once it is created. The directory contains:
On OS/2 and Windows 32-bit operating systems:
The instance directory is located in the x:\sqllib directory, where x: is the drive where you installed DB2.
On UNIX operating systems:
The instance directory is located in the INSTHOME/sqllib directory, where INSTHOME is the home directory of the instance owner.