Juke Management

Think Outside the Box

Jukebox management systems also cache data on hard disk to improve the apparent speed of the jukeboxes under management. Optical storage devices tend to be slow. Even fast optical drives like 5.25-inch magneto-optical can’t compete with hard drives in terms of speed. And then there is the latency in a jukebox — the time it takes for the system to locate, load and spin up a disc. Caching helps smooth over the obstacles that can make using a jukebox a slow and painful experience.

Technology doesn’t stand still, and jukebox management software has to progress to keep up. DVD-RAM is the latest optical technology to hit the market, and management software is just catching up with this new format. Magneto optical is also a moving target, with 5.2 GB drives introduced last year and a new generation of drives expected next year.

Just keeping up with the technology is tough enough, but several jukebox management software vendors are even more ambitious. They’re moving away from simply operating jukeboxes and toward delivering broader storage management options. At the cutting edge, they’re offering hierarchical storage management features, letting you migrate older, lesser-used files to slower, less expensive storage media such as tape.

Jukebox management remains the core need for and competency of jukebox management products, but more sophisticated users may be able to take advantage of the advanced caching and mixed-media capabilities of the leading-edge products. Read on for a lab-based test of three systems along with a preview of four systems now in their final stages of development.

Kofax is well known as a maker of software components for document management systems. The Irvine, CA-based company offers document capture products, image processing hardware and software, and Ascent Storage, a jukebox management system.

Ascent Storage is designed for system administrators who can’t take the time to micro-manage their jukeboxes. Much of Ascent Storage is turnkey — insert a disk, tell the system to make the disk into a “share” (Kofax’s term for a volume to be accessed by users), and then use hierarchical storage management to migrate files from its cache to media. Although the jukebox administrator can adjust caching parameters, the process is kept as simple as possible. There are no complex scheduling screens or customizable policy editors to confuse the user. It is all handled in a simple dialog/properties screen, and there are just three or four parameters to adjust.

Ascent’s disk management is at the recordable surface level. When you’re managing double-sided media, such as MO discs, they appear as two independently recordable surfaces. However, there is no jukebox slot management, and it is not always apparent which recordable surfaces are on the same piece of media. Keeping track of media requires careful planning from the jukebox administrator. If you need to export a share, it can be tough to know what’s on the other side of the disc.

Kofax uses its own proprietary format on all media. On the plus side, each recording surface retains its own directory. If you do move a piece of media from one Ascent Storage system to another, the other system will be able to recreate the directory and share data. On the downside, only Ascent can read your discs.

New for Ascent Storage is DVD-RAM support. So far, Kofax supports Plasmon and NSM DVD-RAM jukeboxes. The discs are formatted with Kofax’s proprietary format. UDF is not available, so moving discs from one system to another is still subject to the same limitations as with MO. With single-sided DVD-RAM, Ascent Storage’s lack of slot management is less of a problem. DVD-RAM support is also an indication that Ascent Storage will be able to adapt to new storage technologies as they come out, protecting your investment in the software.

In our tests, Ascent Storage was fast and scaled well. File save operations always went to the cache first, where the combined effects of disk access and the speed of Ascent Storage’s file system resulted in performance only a little slower than direct access to hard disk storage. Migrating files to optical did slow down Ascent Storage, but this is an intermittent operation and can be controlled by the jukebox administrator.

Ascent Storage is deceptively simple from the point of view of the user interface. The system doesn’t confront you with many of the controls, radio buttons, check boxes and dialogs familiar to other jukebox management systems. All the functions are handled transparently by the system administrator. Of all the jukebox management systems, Ascent Storage comes closest to plug-and-play.

Smart Storage has changed its product lineup dramatically in recent months. Among the new capabilities are DVD-RAM and magneto-optical support as well as interactive file management. These are big steps for a product that a year ago was basically a CD jukebox manager with some disk-at-once recording capability.

The new DVD-RAM and MO support lets users and applications interact with the jukebox media under management. Files can by dynamically added and removed from the jukebox volumes, and system administrators no longer have to carefully plan file migration. File migration is now part of a formal caching system, as in other jukebox management systems. It is easier to use, more automated and more intuitive than previous versions of the software. Even when file migration is not used (and the user interacts with the jukebox directly), a hard disk cache is maintained to speed reading and writing. This cache is entirely automated and transparent to the user.

Unlike the other storage management systems, SmartStor relies solely on non-proprietary disk formats. DVD-RAM disks are formatted with UDF, magneto optical disks with NTFS and CDs with ISO9660. The advantage is that all media are universally portable. The disadvantage is that you lose some performance enhancements that can be gained from a proprietary format. NTFS was not specifically designed for magneto optical media. UDF was designed for optical media, but it was not designed for the multi-disc volumes commonly found in jukebox operations.

Smart Storage is still in the process of building support for rewritable media. DVD-RAM can be written to using the familiar Windows NT interface. However, erase and overwrite is still not available at the file level. DVD-RAM volumes can be erased from the SmartStor administrator program. Full rewritability will become available when Smart Storage adds UDF 2.0 support later in the year. Magneto-optical disks, which are formatted using NTFS, have full read/write capability now.

Unlike some other jukebox management systems that support every type of jukebox from a single application, Smart Storage is shipping separate applications: SmartStor Archive (for CD/DVD) and SmarStor Archive for MO. According to Peter Smails, vice president of Smart Storage’s sales and product management, most users don’t mix MO and CD/DVD. This may change if users start replacing MO with DVD.

OTG’s Disk Xtender is a full-fledged storage management system. While Disk Xtender has yet to support DVD, it does offer many functions that are missing from ordinary jukebox management systems. For example, Disk Xtender will manage magnetic storage. It not only uses a hard disk for cache, it will actually add files on a disk to its own internal database. This lets Disk Xtender migrate files from, say, one RAID system to another. It accomplishes this by working with storage volumes rather than storage devices. Device management is left to modules within the product.

From within Disk Xtender’s administrator, you create an “extended volume” by combining magnetic disks, optical media, tape media and even CDs. Within each extended drive, you create migration rules for moving files from one storage medium to another. Other jukebox management systems give you some of this functionality, but they’re generally not as comprehensive.

One of the practical results of working with storage volumes is that the administrator program doesn’t have to be on the same machine as the storage management system. Disk Xtender’s administrator can be run remotely and can manage multiple Disk Xtender servers.

The only drawback of OTG’s administrator program is that it is a Windows- only application. Disk Xtender has no Web-based administration manager.

The downside of Disk Xtender’s many file migration and storage management features is that it makes for a complex product. There are many steps you have to go through before you can put storage capacity on a network. Those steps include creating extended drives, creating move groups, creating move rules and purge rules, etc. This contrasts with a product like Ascent Storage, where all you have to do is to add media to a jukebox and tell the system how many shared drives you want to make. On the other hand, while Ascent Storage will automatically assign discs to shared drives and migrate files from cache to optical media, it only functions at the level of a single server. Disk Xtender is intended for an entire enterprise.

We tested the performance of Ascent Storage 4.0, SmartStor 3.0 and OTG Disk Xtender in the Imaging & Document Solutions Lab. This included writing, rewriting, renaming and erasing files and groups of files of various sizes and file formats. We also tested the systems with multiple clients, challenging them with multiple, simultaneous requests.

There are a number of factors that can affect performance of these systems. The first and most obvious is the speed of your server and the location of the jukebox manager’s cache. In our tests, we kept the cache on ultra SCSI hard drives. If you can put the cache on a RAID 0 stripe set, you can get better performance.

We used the default cache settings, but this can and should be tailored to your requirements. If you have a system with relatively few users or one where most of the activity is concentrated on relatively few files, you can speed performance by reducing the size of the cache and, thus, disk activity needed to find files. Systems with large numbers of users or broad demand for files are better served by large caches.

File size plays a role too. Magneto-optical media come in several different formats; 512 bytes per sector, 1024 bytes per sector and 2048 bytes per sector. Fewer bytes per sector reduces storage capacity somewhat, but systems that have large numbers of small file transactions can be sped up by these types of disks. In our tests we mixed up the different types of disks. In an application environment, you should be able to optimize your storage devices and disk formatting.

Many systems offer you a choice between proprietary and non-proprietary formats. Proprietary formats give better speed but tie you to that software. In our tests, we encountered the whole gamut of disk format support. Kofax only supported its own proprietary format. SmartStor only supported standard formats like NTFS and UDF. OTG supported its own proprietary format and NTFS.

OTG’s Disk Xtender was the fastest system in both throughput and response time. All the systems we tested would be fast enough for small systems with one or two dozen users. In these environments, ease of use and cost are important factors. Both SmartStor and Ascent Storage were easy to use and provided plenty of speed. While Ascent Storage had better automation, SmartStor’s better slot management and reliance on standard disk formats made it easier to manage and more versatile in reading files outside the jukebox management system.

If we were building a storage management system for a large enterprise, our first choice would be OTG’s Disk Xtender. It was faster and offered a greater range of options for system administration and remote management. —L.R.

Operating Systems: NT, Netware
Disk formats: WORM, MO, CD, DVD-RAM
Comment: Easy to set up and easy to use. As close to plug-and-play as jukeboxes can get.
Price: 20 slots = $3,500; 500 slots = $35,000.
Reader Service Number 220 at ProductInfo

Operating systems: Windows NT, Unix, Netware
Disk formats: WORM, MO, CD, DVD-RAM
Comment: Smart Storage supplies separate products for managing MO and CD/DVD: SmartStor Archive (CD and DVD)and SmartStor Archive for MO.
Price: SmartStor Archive = $500–$15,000; SmartStor Archive for MO = $1,000 – $22,000
Reader Service Number 221 at ProductInfo

Operating system: Windows NT
Disk formats: WORM, MO, CD
Tape formats: DLT, DDS, 8 mm, MLR 1
Comment: Disk Xtender is part of a large family of document management products. More comprehensive than jukebox management, Disk Xtender also manages tape libraries. There is no DVD-RAM support.
Price: 100 slots = $9,000; 750 slots = $26,000
Reader Service Number 226 at ProductInfo