2.1 Hardware Specifications
C141-E252 25
Note:
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 HDD 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 5ºC to 40ºC 5 years
• DE surface temperature: from 41ºC to 45ºC 4.5 years
• DE surface temperature: from 46ºC to 50ºC 4 years
• DE surface temperature: from 51ºC to 55ºC 3.5 years
• DE surface temperature: from 56ºC to 60ºC 3 years
• DE surface temperature: more than 60ºC or less than 5ºC
No guarantee (Keep the DE surface
temperature from 5°C to 60°C.)
Even if the HDDs are used intermittently, the longest service life is 5 years.
The maximum storage period without turning the power on is six months.
Note:
The "average DE surface temperature" means the average temperature at the DE surface
throughout the year when the HDDs are operating.