User manual IBM TS7700 OVERVIEW

[. . . ] At its heart, this grid is a move away from a monolithic approach to a more distributed one. Unlike IBM's old peer-to-peer architecture, the individual TS7700 nodes are managed as an integrated whole. Moreover, each node adds capacity to the local grid and sports new gigabit IP links for inter-node traffic. Another important architectural difference is that IBM now virtualizes the location and number of virtual volumes. [. . . ] Also, VSM5 lacks sufficient channels especially in clustered configurations. Performance Leapfrog is the best way to characterize vendor-specified performance. Sun's VSM hardware is based on a disk subsystem design that goes back to its original 1992 Iceberg product. Though revolutionary in design, that product and its many successors consistently failed to deliver competitive performance. As a consequence, Sun either sold on price or would deliver two systems in place of one -- true for both the disk and virtual tape versions. Indeed, Sun is no longer actively marketing this disk subsystem. In addition, customers often complained that when improvements were made to the disk subsystem version, those improvements took too long to show up in VSM. Nonetheless, late last year, Sun finally released software and hardware upgrades that bring VSM5's specifications up to and in some cases exceeding IBM's. Not exactly a huge leap, but worth noting provided it proves out in real world environments. However, real-world experiences rarely match paper specifications. Workloads, block sizes, compression ratios, read/write ratios and architectural differences greatly impact the performance experience. IBM's TS7700 has a traditional front-end, controller, backend design where hosts/servers talk to the front end and real tape drives talk to the back end. Instead, there is only one set of channels that must be divided and dedicated to hosts, real tape drives, local cluster links and remote links. This can result in both under and over provisioning. Under provisioning hurts ©2008 The Tod Point Group www. TheTodPointGroup. com Page 3 performance and over provisioning wastes money. Moreover, when workloads vary over time, users cannot dynamically shift these dedicated resources. Performance in multi-node configurations is interesting. In IBM's case, three nodes can behave like one big node offering three times the number of virtual tape drives and roughly three times the performance. Of course, Sun also scales when more nodes are added, but each node is treated and managed as an individual node. Data De-Duplication Data de-duplication has emerged as one of the hottest technologies in the market today and virtual tape is a prime opportunity. However, neither IBM nor Sun offers data deduplication for their mainframe virtual tape solutions. Sun recently announced a deal with Diligent Technologies, but this is just a reseller agreement and not an OEM agreement. Thus, as things stand today, Sun cannot integrate Diligent's software into its VSM. IBM, on the other hand, has had various forms of data reduction running for years in its Tivoli Storage Manager (TSM) and although TSM formed the software basis for the previous IBM virtual tape servers, the TS7700 has purpose built firmware. [. . . ] We also note that Sun's web site and collateral materials often contain errors regarding VSM. Bottom Line IBM ranks highly on a vision and execution basis. It has listened well to the market and responded with an up-to-date solution. IBM is well positioned today and for the future. Sun continues to play catch-up and needs to become more open about its products and strategy. [. . . ]