Fujitsu MCJ3230AP, Product Manual

Page: 42 / 199

Specifications
2-6 C156-E205-01EN
2.1.5 Reliability
(1) Mean time between failures (MTBF)
The MTBF is 120,000 hours or more. Failure due to disk errors is not included.
Conditions
$
Power-on time: 200 hours/month or less
$
LD-on time: 20% or less of power-on time
$
Environment Temp.: 25°C
Note:
The MTBF is defined as follows:
1) Operating time is the total time power is applied.
2) Device failures indicate that devices require repair, readjustment, or
replacement. Failure due to external factors such as minor defects during
device handling, operation outside environmental specifications, power
failure, host system errors, and interface cable errors are not included.
(2) Service Life
Under appropriate handling and operation, disk cleaning and optical head
cleaning, overhaul of the drive is not required for the first five years.
(3) Data security at power failure
Except for the data of the block to which write operation is in progress, all data on
the disk is secure from power failure. This does not apply if power failure occurs
during disk initialization (formatting) or defect processing (alternate block
allocation).
total operating time in all fields (hours)
MTBF=
number of device failure in all fields