| The Software Spectrum -
Purchasing processes are shifting from hardware-centric decision making to identifying best platforms for software and applications. -
The underlying hardware must be matched with effective software management systems. -
Storage software helps administrators effectively get control of their storage domains. 3.1 Framework for Storage Management Software -
Storage management breaks down to infrastructure management, transaction management, and recovery management. -
Infrastructure management has a platform focus and includes SAN management and resource management. -
Transaction management has an application focus and includes data coordination and policy management. -
Recovery management has an availability focus and includes data protection and high availability. 3.2 Storage Network Management -
SAN management provides network-centric administration features. -
Discovery identifies all devices within a storage fabric. -
Zoning and configuration determines which storage devices can access and modify each other. -
Zoning can take place through port-based (hard) or WWN (soft) mechanisms. -
SAN topologies serve as a useful tool for mapping physical layouts of storage. -
Monitoring keeps administrators aware of the general health of the SAN. -
Protocol conversion takes place in the SAN between Fibre Channel and IP transports. -
Different device types (iSCSI and Fibre Channel) and device attachment methods (direct or via a SAN) require different protocol conversion mechanisms. -
Documented storage policies and procedures, including cabling and labeling of devices, helps speed recovery in the event of disaster. 3.3 Storage Resource Management -
Storage resource management helps centralize control of storage devices. -
SRM applies to HBAs, SAN switches and routers, and storage subsystems. -
Subsystem efficiency can be tracked through SRM and can aid in capacity planning. 3.4 Data Coordination -
Data coordination takes place through file systems and volume management. -
File systems deliver abstraction between logical volumes and files. -
Volume management delivers abstraction between disks/LUNs and logical volumes. -
File systems and volume management aggregate storage resources to common presentation layers . 3.5 Storage Policy Management -
Storage policies use information from resource management to enhance efficient use of storage. -
Policies include security and authentication; capacity, content, and quota management; and quality of service for storage and storage networks. -
Storage policies are implemented and maintained through an ongoing process. -
Capacity management optimizes the use of existing storage resources. -
Security and authentication policies guarantee privacy and data integrity. -
Quality of service features enable delivery of guaranteed resources. 3.6 Data Protection -
Data protection schemes present various cost-availability tradeoffs. -
Tape backup delivers low “cost-per-megabyte storage with low speeds and long restore times. -
Tape cartridges provide flexibility for onsite and offsite storage. -
With SANs, tape libraries can be shared across the infrastructure, including backup for NAS. -
Disk backup has a high cost per megabyte with high speeds and short restore times. -
Point-in-time and snapshot backup tools enable sequential rollback to restore databases to predisaster or precorruption states. -
Hierarchical storage management helps minimize total storage costs by moving infrequently accessed data to lower cost media. 3.7 High Availability -
For guaranteed uptime, disk backup solutions require mirroring or replication, or both. -
Mirroring provides the highest availability via instant restore times. -
Synchronous and asynchronous replication trade restore time for distance and enable remote backup solutions for site-specific disasters. 3.8 Virtualization -
Virtualization is often misunderstood due to bundling of other storage software features in the term . -
Basic virtualization is the homogeneous presentation of heterogeneous storage. -
Data-protection features like backup or availability features like mirroring and replication can reside on top of a virtualization layer. -
Virtualization can be deployed across host, fabric, and subsystem layers. -
Options exist for customers to balance storage control points through different virtualization deployments. |