Checking the Reliability of the Tape Data

After the Streaming Tape Drive Utility completes a list or restore operation, the message ªReliability: Tape drive recovered from xxx soft errorsº appears, with xxx representing the number of 512-byte blocks that could not be read successfully on the ®rst attempt. However, the tape drive was able to recover the data successfully using either a read retry or ECC. The hardware speci®cations allow up to one soft error for every 102 KB of data, but testing has shown that a typical list or restore operation of 4 GB of data would only have one soft error for every 1 MB to 14 MB of data. For example, if a tape is full (it has 4 GB of data), it may have over 200 soft errors.

When the Streaming Tape Drive Utility is exited, a W660 B4/S055/E010 message is logged to record the number of soft errors encountered while the utility was running. If you format the W660 message using the Long Format Mode of the Scan System Log Data Utility in the Controller Events bucket, the following line appears:

DATA ERRORS: XXX

UNDERRUNS: XXX

PARITY ERRORS: XXX

The DATA ERRORS ®eld shows the number of soft errors that were recovered using a read retry. The UNDERRUNS ®eld is not used for the TR-4 Tape Drive and always shows 0. The PARITY ERRORS ®eld indicates the number of soft errors that were recovered using ECC.

Listing a Tape

The directory information for each ®le on the tape is located immediately before the ®le data for each ®le. It does not have a separate directory. Therefore, listing the data on the tape requires reading all of the data on the tape. A full tape of

4GB of data would require about 2.5 hours to list the tape at the rate of 30 MB per minute. It is recommended to list the tape after each backup. The list can be used to verify that the data can be successfully read if required.

Erasing a Tape

Erasing a tape takes approximately three minutes. The process writes an End-of-Data marker at the beginning of the tape, winds the tape to the end, and then rewinds back to the beginning in order to retension the tape.

Messages

This section describes the messages speci®c to the TR-4 Tape Drive.

W679 W679 STREAMING TAPE DRIVE

E019 ± Peripheral device write fault. This normally

ERROR B4/S056/Exxx

indicates a hardware problem with the tape cartridge.

Severity: 3

Explanation: The attempted streaming tape drive operation cannot be performed.

The event (Exxx) in the message indicates the following:

E020 ± No write current.

E021 ± Excessive write errors.

E022 ± Logical unit not ready, cause not reportable.

E023 ± Logical unit is in process of becoming ready.

E024 ± Logical unit not ready, initializing command required.

14TR-4 Tape Drive User's Guide

Page 28
Image 28
IBM 4690 manual Checking the Reliability of the Tape Data, Listing a Tape, Erasing a Tape, Messages

4690 specifications

The IBM 4690 is a renowned point-of-sale (POS) system that has been pivotal in the retail and hospitality industries since its introduction in the late 1980s. Notably associated with IBM’s family of retail hardware and software solutions, the 4690 has transformed the modern retail environment, providing a robust platform for transaction processing and inventory management.

One of the main features of the IBM 4690 system is its powerful software architecture. Designed to efficiently handle high transaction volumes, it integrates seamlessly with various peripheral devices such as barcode scanners, receipt printers, and payment terminals. The system's user-friendly interface allows staff to process sales quickly and efficiently, enhancing the overall customer experience.

In terms of technology, the IBM 4690 operates on a proprietary operating system that supports a variety of programming languages, allowing retailers to customize applications to meet their specific needs. This flexibility not only streamlines operations but also enables retailers to implement specialized services such as loyalty programs and promotions. The hardware is designed for durability and reliability, essential in high-traffic retail environments.

Another significant characteristic of the IBM 4690 is its robust reporting capabilities. The system provides comprehensive sales reports, inventory analyses, and customer insights, all of which are essential for strategic decision-making. This analytical power helps businesses identify trends, forecast demand, and optimize stock levels, ultimately leading to improved profitability.

Furthermore, the IBM 4690 is known for its strong security features. By utilizing advanced encryption technologies and compliance with industry standards, the system helps protect sensitive customer data and payment information, ensuring a safe transaction environment.

The longevity and adaptability of the IBM 4690 system underscore its value in the retail sector. Even with newer technologies emerging, many businesses continue to rely on the robust functionality and proven performance of the 4690. With ongoing support and upgrades, the system remains a reliable choice for retailers looking to enhance their operational efficiency while delivering excellent customer service.

In summary, the IBM 4690 stands out due to its feature-rich software, durable hardware, robust reporting and analytics, and stringent security measures. These characteristics make it an indispensable tool for retailers aiming to thrive in an ever-evolving marketplace.