Guidelines for Chunk/Dbspace layout

Does anyone have a set of guidelines for database layout across multiple disks? Specifically: I have 3 disks on a production system, running OnLine 4.1. One disk, a 400Mb devices, contains root, /usr, /usr/local, and swap. The other two disks are identical 1.2Gb devices. The intent is to have one disk mirror the other. Now, should I define one chunk and one dbspace for the entire 1.2Gb (the "c" partition), thus resulting in one primary chunk and one mirror chunk? Should I split the disk into at least two chunks for two dbspaces - the root dbspace and one other, say the "g" and "h" partitions? If I'm completely mirroring the primary device ( and therefore, the root dbspace ) do I still need to move the logical logs to another location? Basically, I'd like to hear experiences, and from the Informix folks - performance considerations. Thanks in advance - I'll summarize all responses. -- In-Real-Life: John Bossert, Thalatta Corporation, (+1 206.455.9838) Domain: bossert@Thalatta.COM Path: ...!sun!sunup!thebes!bossert