WORM optical disks once were the only electronic storage media approved by the
Securities and Exchange Commission. Now the write-once, read-many-times media faces
lower-cost competition from tape cartridges that mimic WORM disks, according to a storage
Storage Technology Corp. of Louisville, Colo., has developed nonrewritable, nonerasable
archival tape drives and media to prevent accidental or purposeful erasure of data, said
Joel Brunson, federal systems director for StorageTek.
The VolSafe tape drives and media have logical as well as physical protection against
unwanted overwrites. The logical security comes from microcode on the tape transport and a
bit setting put on the tape leader at the time of initialization, Brunson said.
VolSafe cartridges also have a yellow notch that alerts human operators and tape drives
to treat them as WORM media. StorageTek will make the VolSafe drives initially for its
RedWood transport subsystems and 50G helical tape cartridges. The RedWood subsystems
attach via SCSI or Escon channels to StorageTek PowderHorn robotic tape silos.
The PowerHorn is StorageTeks library storage module, which stands 8 feet high and
measures 12 feet in diameter.
The Social Security Administration maintains 28 PowderHorn storage silos at its
Woodlawn, Md., campus, StorageTek officials said. Each tape silo can hold up to 6,000 tape
A robotic arm mounted in the third-generation silos can grab a cartridge, mount it in
the tape transport and return it to the library as many as 450 times per hour, Brunson
Im afraid were going to have to weld it to the floor pretty soon,
because the torque is going to lift it, he said.
As of this June, agencies had bought 669 StorageTek PowerHorn tape libraries, 5,368
StorageTek 18/36-track tape drives, 1,112 TimberWolf tape transport subsystems and 286
RedWood transport systems, Brunson said.