REVIEW

Unix HSM Software Eases Data Management Woes

C ompress files. Move files to the server. Delete files. Get a bigger disk. Get another disk. Story of your life.

But Hierarchical Storage Management (HSM) software--a worthy mainframe era remnant--promises to help fight the Sysiphian battle against runaway data management costs.

HSM keeps recently used files on your fast, local or network server hard drive. Files used infrequently get moved to slower, cheaper media, like magneto-optical (MO) or tape. Unlike the NetWare market, which has just started to see the likes of HSM (See HSM Migrates to NetWare Platform , March issue.), Unix network managers have had HSM products for several years.

Some HSM products work only with a file server, so you can manage, for instance, an NFS-exported file system. Some are complete client/server solutions where trusted clients can migrate files to a server-attached jukebox or auto-changer. Each method targets a different audience. Server-centric systems are best where your clients work mostly with files kept on a central Network File System (NFS) server. Distributed systems are better where workgroups manage their own machines, but want a centrally managed store for migration and backup.

We evaluated SunOS versions of Alphatronix Data Migration Manager, Epoch EpochMigration Manager, OpenVision HSM Extension, Advanced Software Concepts NetArchive, QStar MastarMind and HIARC Sparcus over several months at our University of Wisconsin labs. Alt hough these products function similarly, implementations and device support vary. Most only support one migration level.

We ran these products on a Sun SparcStation 10 running SunOS 4.1.3-U1 with 64 MB of memory and a 1-GB internal hard disk. We set up a minimal file system with files of varying size and type. We used a Hewlett-Packard 20XT magneto-optical (MO) jukebox as our first-level media, and an Exabyte 10e tape auto-changer for the products that supported another migration level.

Our Analysis