Because backing up data on multiple coservers is much more complex, some Extended Parallel Server users use third-party storage managers. The following usage requirements also affect your decisions about the storage manager and storage devices:
Balance these factors against the number of storage devices and storage-manager instances. The architecture of some platforms limits where you can attach devices, but the number of coservers increases processing requirements. The storage-manager sections of the ONCONFIG file should reflect these considerations.
Although some nodes in a massively parallel processing (MPP) system might not be running coservers, they might be able to run part of the storage manager.
Because disks are slower than the high-speed interconnect, they could create a bottleneck in the interconnect. Distributing devices across multiple nodes might reduce the amount of traffic across the interconnect and allow more parallelism.
Although Decision Support System (DSS) databases might not be mirrored, they might be easier to re-create from the original external source than to restore from backups if they are corrupted or damaged. For Online Transaction Processing (OLTP) systems, regenerating data from external sources is rarely possible.
If you are running an OLTP system with many transactions evenly distributed across coservers, your storage manager and storage-device requirements are different from a DSS, which usually generates few transactions.
In addition, if logstreams are the same size on each coserver but activity is not evenly distributed, space and resources are wasted. You should adjust them for efficiency.