Reliability; Mean-Time-Between Failures; Mean-Time-To-Repair - Seagate STT20000N Product Manual

Chapter 2

Reliability

Mean-Time-Between Failures

Mean-Time-To-Repair

Page 14
The STT20000 SCSI minicartridge drive is designed for maximum reliability and
data integrity. The following table summarizes the reliability specifications.
Feature
Non-recoverable error rate
Error recovery and control
Mean-Time-Between-Failures
(MTBF)
Mean-Time-To-Repair (MTTR)
The Mean-Time-Between Failures (MTBF) is greater than 200,000 hours. This
specification includes all power-on and operational time but excludes maintenance
periods. Operational time is assumed to be 20% of the power-on time. Operational
time is the time the tape is loaded. MTBF is highly dependent on operational time,
as operational time increases above 20% of the power on time the MTBF is
reduced, conversely as the operational time is reduced the MTBF increase, as an
example at a operational duty cycle of 12% the STT20000 MTBF can equal 250,000
hours.
Note: Seagate does not warrant the stated MTBF as representative of any
particular unit installed for customer use. The failure rate quoted here is
derived from a large database of test samples. Actual rates may vary from
unit to unit.
The Mean-Time-To-Repair (MTTR) is the average time required by as qualified
service technician to diagnose a defective drive and install a replacement drive. The
MTTR for the drive is less than 0.33 hour (20 minutes).
The STT20000 SCSI minicartridge drive is a field replaceable unit. If a problem
occurs with a subassembly or component in the drive, the entire unit should be
replaced. The faulty drive should be returned to the factory in its original packaging.
Contact your distributor, dealer, your computer system company, or your Seagate
sales representative to arrange the return.
Specification
15
< 1 in 10 bits
Reed-Solomon Error Correction Code
techniques
Error monitoring and reporting (Error Log)
Media pre-written
Retry on read
Data randomization
Greater than 250,000 hours
Less than 0.33 hour
STT20000A Product Manual
Specifications