Fujitsu MBA3147NC 用户手册

(1) 

Mean Time Between Failures (MTBF)  

 

MTBF of the HDDs during its lifetime is 1,400,000 hours (operating:  24 hours/day, 7 days/week 
average DE surface temperature: 50°C or less). 

 

Continual or sustained operation at case DE surface temperature above 50

°C may degrade product 

reliability. 

 

The MTBF is defined as: 

Operating time (hours) at all field sites 

MTBF= 

The number of equipment failures from all field sites 
 

 

Failure of the equipment means failure that requires repair, adjustments, or replacement.  
Mishandling by the operator, failures due to bad environmental conditions, power trouble, host 
system trouble, cable failures, or other failures not caused by the equipment are not considered. 

(2) 

Mean Time to Repair (MTTR) 

 

MTTR is the average time taken by a well-trained service mechanic to diagnose and repair an 
HDD malfunction.  The drive is designed for a MTTR of 30 minutes or less. 

(3) Service 

life 

 

The service life under suitable conditions and treatment is as follows. 

 

The service life is depending on the environment temperature. Therefore, the user must design the 
system cabinet so that the average DE surface temperature is as low as possible. 

•  DE surface temperature: from 5°C to 40°C 5 

years 

•  DE surface temperature: from 41°C to 45°C 

4.5 years 

•  DE surface temperature: from 46°C to 50°C 

4 years 

•  DE surface temperature: from 51°C to 55°C 

3.5 years 

•  DE surface temperature: from 56°C to 60°C 

3 years 

•  DE surface temperature: more than 60°C, or less than 5°C No 

guarantee 

 

(Keep the DE surface  

 

temperature from 5

°C to 60°C.) 

 
 

Even if the HDD is used intermittently, the longest service life is 5 years. 

 

The maximum storage period without turning the power on is six months. 

C141-E270 

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