Re: Volume Manager/Sun Useable Slices....

MS CARLEEN C AVANT wrote: > > Question: > Basically, our platform is a Sun E4000 (4 processors) utilizing Solaris > 2.6, Informix 7.24, Multipack disk storage controlled by Volume Manager > software. As DBA's we would like to implement more than one dbspace per > database to capitalize on the parallelization of the Informix 7.x > environment. We are told by our system administrator that there are only 6 > useable slices on the Sun platform. With the requirments for file systems > and raw space, the only way to achieve multiple dbspaces per database may > be by using offsets. We had hoped to avoid using offsets. By chance are we > overlooking another approach? There is no cost or overhead to using chunks beginning at offsets, per se. There is no runtime performance difference between operating different chunks on several partitions on one disk -vs- using offsets on the same one disk. Also using offsets the performance interaction between different chunks is documented in the engine itself and reported on by onstat and oncheck. Keep in mind though that offsets cannot help you access parts of a disk beyond 2GB (2097150K). You still have to have VM partition the device into 2GB or smaller logical devices for Informix to use. BTW standardizing on fixed sized devices for Informix Chunk assignment (ie make them 2097150K exactly [or slightly smaller to satisfy disk array alignment requirements] but all the same size). In this way if you need to restore from one machine to another it will be far less hassle than scrounging and having to repartition disks. Art S. Kagel