Fujitsu MHN2150AT Manual/User Guide - Page 29

Reliability, environments, defects in the power supply host system, or interface cable.

Page 29 highlights

1.7 Reliability 1.7 Reliability (1) Mean time between failures (MTBF) Conditions of 300,000 h Power-on time Operating time Power on/off Environment 250H/month or less 3000H/years or less 20% or less of power-on time 1/day or more needed. 5 to 55°C/8 to 90% But humidity bulb temperature 29°C or less MTBF is defined as follows: Total operation time in all fields MTBF= (H) number of device failure in all fields (*1) *1 "Disk drive defects" refers to defects that involve repair, readjustment, or replacement. Disk drive defects do not include failures caused by external factors, such as damage caused by handling, inappropriate operating environments, defects in the power supply host system, or interface cable. (2) Mean time to repair (MTTR) The mean time to repair (MTTR) is 30 minutes or less, if repaired by a specialist maintenance staff member. (3) Service life In situations where management and handling are correct, the disk drive requires no overhaul for five years when the DE surface temperature is less than 48°C. When the DE surface temperature exceeds 48°C, the disk drives requires no overhaul for five years or 20,000 hours of operation, whichever occurs first. Refer to item (3) in Subsection 3.2 for the measurement point of the DE surface temperature. Also the operating conditions except the environment temperature are based on the MTBF conditions. (4) Data assurance in the event of power failure Except for the data block being written to, the data on the disk media is assured in the event of any power supply abnormalities. This does not include power supply abnormalities during disk media initialization (formatting) or processing of defects (alternative block assignment). C141-E120-02EN 1-9

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1.7
Reliability
C141-E120-02EN
1-9
1.7 Reliability
(1)
Mean time between failures (MTBF)
Conditions of 300,000 h
Power-on time
250H/month or less
3000H/years
or less
Operating time
20% or less of power-on time
Power on/off
1/day or more needed.
Environment
5 to 55°C/8 to 90%
But humidity bulb temperature
29°C or less
MTBF is defined as follows:
Total operation time in all fields
MTBF=
(H)
number of device failure in all fields (*1)
*1
“Disk drive defects” refers to defects that involve repair, readjustment, or
replacement.
Disk drive defects do not include failures caused by external
factors, such as damage caused by handling, inappropriate operating
environments, defects in the power supply host system, or interface cable.
(2)
Mean time to repair (MTTR)
The mean time to repair (MTTR) is 30 minutes or less, if repaired by a specialist
maintenance staff member.
(3)
Service life
In situations where management and handling are correct, the disk drive requires
no overhaul for five years when the DE surface temperature is less than 48°C.
When the DE surface temperature exceeds 48°C, the disk drives requires no
overhaul for five years or 20,000 hours of operation, whichever occurs first.
Refer to item (3) in Subsection 3.2 for the measurement point of the DE surface
temperature.
Also the operating conditions except the environment temperature
are based on the MTBF conditions.
(4)
Data assurance in the event of power failure
Except for the data block being written to, the data on the disk media is assured in
the event of any power supply abnormalities.
This does not include power supply
abnormalities during disk media initialization (formatting) or processing of
defects (alternative block assignment).