Vinum, is a logical volume manager, also called Software RAID, allowing implementations of the RAID-0, RAID-1 and RAID-5 models, both individually and in combination. Vinum is part of the base distribution of the FreeBSD operating system. Versions exist for NetBSD, OpenBSD and DragonFly BSD. Vinum source code is currently maintained in the FreeBSD source tree. Vinum supports raid levels 0, 1, 5, and JBOD. Vinum is invoked as gvinum (GEOM Vinum) on FreeBSD version 5.4 and up. The distribution of data across multiple disks can be managed by either dedicated hardware or by software. Additionally, there are hybrid RAIDs that are partly software- and partly hardware-based solutions. With a software implementation, the operating system manages the disks of the array through the normal drive controller (ATA, SATA, SCSI, Fibre Channel, etc.). With present CPU speeds, software RAID can be faster than hardware RAID.
Introducing Logical Data Structures, the breakthrough user-centered approach to modeling enterprise databases. Asking the right questions -- and understanding the answers. Real-world examples and techniques for modeling today's enormous data sets -- and tomorrow's. Brings a requirements approach to database design and modeling. This book introduces Logical Data Structures (LDS), a powerful new approach to database design that can dramatically improve the cost-effectiveness and business value of any enterprise database system or database-driven application. The authors introduce a new notation, new diagramming approach, and new user-centered, high-ROI techniques for modeling even the most complex, high-volume database applications. This book starts from first principles, asking and answering crucial questions like: 'To best serve users, how should the process of data modeling work? To create good, economical software systems, what kind of information should be on a data model? To become an effective data modeler, what skills should you master before talking with users?' Next, it teaches data modeling using LDS, designed to encourage a user-centered, requirements approach that leads directly to more effective applications. The authors walk you through the entire process of creating and enhancing a data model. For all database administrators, analysts, designers, and architects, and for all IT managers responsible for enterprise database system management or deployment. John Carlis is an associate professor of computer science at the University of Minnesota. For over 20 years, he has taught, consulted, and conducted research on database systems, data modeling and database language extensions. Joseph Maguire is Program Manager for Microsoft's Repository and Open Information Model, a set of industry-standard models developed jointly by Microsoft and other leading vendors.