White Paper

 

Developments in Storage Systems and Software

March 2000



To cope with the demand for increased storage capacity, continuous availability, and improved performance, scalability, manageability, and ease-of-use, enterprise system administrators can take advantage of progress made in disk and tape array systems, libraries and jukeboxes, and storage management software.

Consolidated Disk and Tape Arrays

Because consolidation is a key trend in enterprise storage management and centralized administration is considered a must, organizations are purchasing both servers and storage in larger units. There are many advantages to this consolidation and centralization. Larger systems can more easily justify the overhead associated with more sophisticated implementations while providing manageability, scalability, and serviceability. In addition, centralized sites experience greater uptime and increased performance, which translates to lower total cost of ownership (TCO).

With data and storage availability becoming the most important characteristics, RAID has gained very wide market acceptance in all segments, with mirroring (RAID 1) remaining a strong contender. This year, disk arrays will offer higher levels of system redundancy (no single point of failure) and additional intelligence, with automated volume management and adaptive RAID functionality overcoming the RAID 5 write performance issue. Price per megabyte has decreased at an average rate of 30 percent per year for the past 3 years and will continue through 2002, with some configurations reaching levels below 10 cents per megabyte.

Borrowing from the RAID concept, tape-system manufacturers are developing redundant arrays of independent tapes (RAIT) for data-transfer-intensive and continuous backup applications when you don't want a backup operation to stop With RAIT, even if one tape in the array fails, you can restore all the data.

Libraries and Jukeboxes

Falling prices will drop the cost of tape libraries and [optical jukeboxes to an affordable level for workgroups. Libraries and jukeboxes will offer multiple simultaneous paths to an array of drives for very high performance and continuous backup operations. One major advantage of libraries and jukeboxes is their ability to be shared among multiple backup servers, allowing administrators to consolidate backups and monitor them with more consistent policies and procedures. Major library and jukebox vendors include ADIC, HP, IBM, Overland, Quantum/ATL, and StorageTek.


Management Software

Robust configuration management and strong monitoring capabilities are part of the new software developed to centrally manage storage resources. Management software can now detect imminent failures, performance bottlenecks, and out-of-bound conditions by extrapolating from the data that the network and storage devices provide and by taking predefined actions to deal with these events. Automation in optimizing functions, such as reconfiguration and load balancing, is one of the most anticipated improvements in management software. Look for new developments in three areas:

~ Data management

This year several trends will materialize aimed at improving backup, data replication, mirroring, and remote vaulting. This has been covered in another White Paper (Traditional Applications- New storage Needs)

~ Hierachical Storage Management (HSM)

The Internet and e-commerce have created an environment in which not only is more data generated, but also more data needs to be retained and readily accessible. In this environment, HSM becomes economically desirable

HSM automatically move data from high-cost to low-cost media, based on parameters an administrator sets. These systems provide different data storage tiers. As you move down the tiers, storage capacity increases, cost decreases, and retrieval time lengthens. For example, an HSM system might move data that hasn't been accessed within the past month from a server's hard disk to a less costly but slower first-tier storage device (e.g., an optical jukebox). After another period of time elapses--perhaps three months--an HSM system might move that data to a second-tier device (e.g., a tape library). HSM is also set to move data in the opposite directions - from first or second tier to disk drive- according to the need or according to a pre-established policy, for example, calling back an application or a database at the end of each month at payroll or accounting time. HSM with files is a mature product capability. The ability to save off and restore databases or portions of databases is relatively new and you should take the time to make sure that the capabilities of the product you are considering will meet your needs

~ Storage Resource Management (SRM)

SRM software monitors the health, availability, performance, and configuration of storage systems to provide built-in policies and optimization advice. It helps administrators better diagnose their system performance issuesand better manage their storage resources. SRM, the fastest growing category of storage management software, is an increasingly critical segment of the storage management market and is becoming a key ingredient to network and storage manageability.

~ File management

In heterogeneous environments, a major problem is finding a system to efficiently handle a variety of file system formats. In a NAS system, the native file system takes care of this. However, in SAN systems, the problem has not yet been solved on a widespread basis although many solutions have been put forward, ranging from an on-the-fly conversion from one file system to another to the use of a generic independent file system--sometimes referred to as a "distributed file system." Many development activities are under way, some of which are expected to mature this year 5 These file systems will allow the widespread use of data sharing. CrosStor and Veritas lead the development of generic independent file systems.

 

 

 

 

By: Farid Neema

PERIPHERAL CONCEPTS, INC.
351 Hitchcock Way, Suite #B-200
Santa Barbara, California, 93105
Tel: (805) 563-9491
fneema@silcom.com

This article was published in the Marh issue of Windows2000 Magazine