Cartridge Capacity Scaling; Cartridge Memory (Cm); Write-Once Read-Many (Worm) - IBM 3592 Maintenance Information

Table 13: Types of data tape cartridges. Use with Figure 1 on page 26. (continued)
JZ Platinum
(Silvery gray)
Notes:
• The standard read/write cartridge might be called "data cartridge" in other documentation.
• 1 GB = 1 000 000 000 bytes. 1 000 GB = 1 TB (1 000 000 000 000 bytes).
• Although you can format the same data cartridge in any of the native capacities, if you change the
Default Density of the drive, a data cartridge is limited to that particular density. See "Setting default
density" on page 249 for information about default density.
• The terms 'Extended' and 'Advanced' are used in the Description column to denote increased
capacity.
• When cartridges are formatted for the 55F tape drive, native capacities for JD, JL. and JZ cartridges
are increased.

Cartridge capacity scaling

The 3592 tape drive supports capacity scaling of individual JC and JD data cartridges. Capacity scaling
allows the customer to contain data in a specified area, at the beginning of the tape. This feature reduces
'locate' and 'read' times.
This capacity scaling is not supported for either economy or WORM tape cartridges.

Cartridge memory (CM)

Each 3592 data cartridge contains a passive, silicon storage device called cartridge memory (CM). This
CM holds information about the cartridge and the media in the cartridge, and holds statistics about media
performance.
The cartridge and media information is stored in a protected, read-only area of the CM. The CM reader
uses a radio-frequency interface to read this information when the cartridge is loaded into the drive.
The media performance statistics are stored in an unprotected, read/write area of the CM. These statistics
are updated by the CM writer just before the cartridge is unloaded. The media performance statistics are
maintained by the Statistical Analysis and Reporting System (SARS) portion of the drive microcode. For
information, see "Statistical Analysis and Reporting System (SARS)" on page 43.

Write-once read-many (WORM)

Some records retention and data security applications require the write-once read-many (WORM)
function of tape data storage. This WORM function is accomplished on the 3592 by a combination of
microcode controls in the drive, and a special WORM tape cartridge.
No physical hardware changes are required to make the drive WORM-capable. All 3592 drives are WORM-
capable.
See Table 13 on page 26 to determine the WORM cartridge types. Use the color of the case and other
markings to distinguish the WORM cartridges.
The WORM tape media is formatted differently than the standard read/write media. This unique format
prevents a WORM cartridge from being written on by a drive that does not have the WORM microcode.
One field in the servo manufacturer's word (SMW) on the tape designates that the media is WORM. Also,
the cartridge memory (CM) has a WORM indicator byte in the cartridge type field. Both of these conditions
must be true for the drive to work with a WORM cartridge. If one condition is true and the other is false, an
ATTN DRV - Invalid Cartridge message posts.
Burnt N/A
Orange
10 TB 15 TB 15 TB Advanced Type
D WORM
Introduction 27