Years ago the mainframe offered the first storage that would later become known as a storage area network (SAN). Few noticed. Even now mainframe storage hardly draws any attention. The ongoing improvements tend to be steady and incremental. An occasional first, like built-in tape drive encryption, but in general nothing revolutionary occurs in z storage.
The last year, however, has seen a resurgence of IBM interest in System z storage. It bought Diligent and turned it into the ProtecTIER product and IBM XIV, another acquisition and interesting grid storage product. Both now can connect with the System z, XIV through Linux on z as the gateway. It also introduced Easy Tier, an SSD product that uses built-in intelligence to automatically detect and move data that will specifically benefit from SSD performance.
Storage enhancements for the z are coming just in time. IBM is targeting HP customers for its System z and POWER7 servers. HP introduced 400 GB SSD for use with the System z through its HP XP storage system. While HP doesn’t have a storage grid product like XIV, it does allow the XP to act as a storage controller for various large arrays behind the XP, in effect creating grid-like storage using various HP storage arrays. It also has data deduplication products. The HP mainframe storage story is here.
ProtecTIER for the z is a deduplication product. It reduces the amount of data you have to backup (after the initial full backup), thereby speeding backup and reducing IT resource consumption.
XIV, however, is the more interesting of the new System z storage options. It allows an organization to put large amounts of varied storage (different disk, capacity, performance characteristics) behind the System z. Don’t expect it to replace conventional mainframe storage as delivered by, say, the DS8700. Rather, it offers a way for an organization to consolidate all its storage behind the z and gain the benefits of storage consolidation for varied workloads and z reliability and availability. XIV, as a storage grid, automatically spread copies of data across the available capacity. This speeds rebuild time, especially now that XIV is incorporating 2TB disks.
The emergence of Linux on System z along with Java has rejuvenated the System z in many ways. It has enabled new and different workloads, makes SOA practical, and enables the z to play in the web 2.0 and mobile computing worlds. The arrival of XIV and ProtecTIER do the same for System z storage, which had been effective but uninspired, with maybe an occasional tape innovation, until now.