EXABYTE CUSTOMER QUALITY ADVISORY MAMMOTH AND MAMMOTH-LT VERSION 
V40Q FIRMWARE ERROR

In an ongoing effort to improve product quality and enhance functionality, 
Exabyte has updated the electronics and firmware in our Mammoth and 
Mammoth-LT tape drives. As part of this effort, we released firmware 
version v40q in February 1999. Despite thorough pre-release testing, we 
recently discovered an error in firmware version v40q that can cause data 
loss in rare circumstances.

Although the probability of data loss is extremely low, the potential 
impact is high. For this reason, we strongly encourage customers who received 
generic Mammoth or Mammoth-LT tape drives manufactured or serviced between 
February and April 1999 to check the firmware in their drives and to upload 
new firmware if required.

DESCRIPTION

During normal write operations, when the host is unable to supply data fast 
enough to keep the tape drive streaming, forward motion stops, a "backhitch" 
tape motion occurs, and the tape drive waits for more data. As soon as the 
host can supply sufficient data, forward motion resumes, a "splice" operation 
is performed, and the tape drive resumes writing.

If a write error occurs while the tape drive is performing the splice operation 
and recovery algorithms are invoked, the tape drive may fail to write a single 
block of data. This data loss is not reported until the user reads the tape, 
either during a verify operation or when attempting to restore data. At that 
point, the tape drive halts operations with a permanent read error (Fault Symptom 
Code 0Bh).

EXPOSURE

To date in Exabyte’s Ongoing Reliability Testing (ORT), the error has occurred 
approximately once per 9,400 tape motion hours. ORT is conducted in a clean 
office environment using good media and following recommended cleaning procedures. 
Both streaming and non-streaming testing is included. The error is more likely 
to occur under adverse conditions for writing data (for example, dirty tape 
drive, poor-quality media) or with hosts that are unable to maintain drive streaming.

CORRECTIVE ACTION

The recommended action for affected Mammoth tape drives is to upload the newest 
level of firmware from this web site. For Mammoth-LT, you must upload the new 
firmware and a new EEPROM image. Follow the instructions in Upgrading Exabyte 
Mammoth or Mammoth-LT V40q Firmware.

CONTACTING TECHNICAL SUPPORT

If you have questions about this Customer Quality Advisory or the codeload procedure, contact Exabyte Technical Support via Exabyte.com. 
