[mythtv-users] Western Digital Red for Myth

[Stephen Worthington]

On Sat, 24 Aug 2013 12:43:25 -0400, you wrote:

>On 8/24/2013 12:38 PM, Stephen Worthington wrote:
>> That said, the desktop drives are now advertised as not being 24x7
>> capable, so I expect that there would be problems getting them
>> replaced if they fail when used 24x7.
>
>Be careful there. Certain drives are being advertized as designed to be 
>used 24x7, but no one ever said the other drives weren't designed to be 
>used in the same manner. Marketing people like to twist words to imply 
>inaccurate meaning without actually stating it.

The specs for desktop drives now seem to have significant
qualifications as to how much you can work them in a year.  For
example, this is from the Seagate ST4000DM000/ST3000DM003 manual:


Rated workload

Average rate of <55TB/year. The MTBF specification for the drive
assumes the I/O workload does not exceed the average annualized
workload rate limit of 55TB/year. Workloads exceeding the annualized
rate may degrade the drive MTBF and impact product reliability. The
average annualized workload rate limit is in units of TB per year, or
TB per 8760 power-on hours. Workload rate limit = TB transferred ×
(8760/recorded power-on hours).


I have not done any calculations to see what that limit would mean,
for my usage of a MythTV drive, but 55 Tbytes does not seem too small
a number.

I am guessing that they have had problems with businesses using
desktop drives in high usage server applications and had complaints
about the failure rates.  So they are now adding these specifications
to cover themselves against getting sued.