A chunk is a physical portion of disk on which Informix stores its data. A chunk can be either a raw partition or a file system file. Informix suggests that a chunk's name be a symbolic link to the actual chunk. For example, if you are using /dev/rdsk/c6t0d0s1 as a chunk, you could create a symbolic link named /dev/informix/chunk1 that points to /dev/rdsk/c6t0d0s1. That way, if there are ever any problems with that disk, you could replace the disk with another one and just change the symbolic link.