February 2001

TEST DRIVE

Ultrium Redefines Tape Storage

by Lowell Rapaport

The main problem with many archiving systems is that they don't scale well. Archive systems mount near-line storage directly to the network, and each near-line storage pool is accessed individually. This is sufficient for applications that have specific storage requirements, but for an enterprise, where additional storage is constantly being added, multiple independent archives are inefficient. Files can't be migrated from one archive to another, and each archive appears as a separate entity to each user or application. This complicates access to information.

As a result, one by one, the companies that make archive management software for optical libraries are redesigning, and in some cases creating from scratch, storage management systems that can better cope with new storage networking options like network attached storage devices and storage area networks. The new systems are more data-center oriented and work at both the hardware and operating system level.

One of the first of these new systems is Infinet 1.0, from Smart Storage, Andover, MA. Like existing archiving systems, Infinet provides file-level migration from online to near-line storage. File migration policies can be defined according to size, age, usage and file type. The system manages near-line media down to the slot level. Multiple pieces of media can be pooled into larger volumes, and individual pieces of media can be partitioned into smaller volumes.

The major sea change in SmartStor Infinet and other evolved storage products is in how files are made available to users and applications on the network. In Infinet, when a file is migrated to a library, a placeholder is left on the original hard drive or RAID subsystem. All access to the near-line storage takes place through these placeholders on the hard drive. Libraries added to the system are simply additional destinations that files kept on online storage can be sent to. The system doesn't have to mount the additional near-line storage to the enterprise LAN, and all storage is virtualized into a single pool.

This approach lets you have as much near-line storage as you need without having to tell your users and applications about it. There is no need to go from computer to computer activating additional drive letters, and you don't have to reprogram applications to see a new volume on the network. Also, when the original hard drive or RAID system capacity is exceeded, the files and placeholders can be easily moved to a newer, larger volume without disrupting the near-line storage.

Over the long term, this new architecture will let Smart Storage create new features that weren't possible with its older SmartStor Archive product. For example, the company plans to develop a distributed storage environment where software agents on other servers will allow direct access to the near-line archive across a network (the network being a regular Ethernet or even a SAN based on gigabit Ethernet or fiber channel hardware). The system can potentially tie in remote network attached storage devices with the centralized storage.

Also on Smart Storage's slate for the coming months is reverse migration, a technique that allows frequently used files to be copied back to local storage. Once this becomes available, Infinet will have a distinct advantage over the caching capabilities of existing archiving systems, which can only copy files back to storage on the archive server. Copying files back to the user's own local storage will speed up access and save network bandwidth.

The one caveat regarding SmartStor Infinet: It is a version 1.0 product, and most of its potential lies in the future. The underlying architecture of Infinet is in place, letting you add near-line libraries without having to mount each library to the network. At this writing, the product only supports CD, DVD and magneto optical libraries and directly attached SCSI and fiber channel storage devices. A February update is expected to add support for tape libraries and reverse migration. Further upgrades will be required to add support for more advanced features, including distributed servers, network attached storage, storage area networks and shared file systems.