[mythtv-users] Re: A warning about Samsung HDDs

[Steve Adeff]

On Tuesday 01 November 2005 23:11, Tony Lill wrote:
> Dewey Smolka <dsmolka at gmail.com> writes:
> > As someone who has professionally destroyed hard drives (most of us
> > here are only practiced amateurs), what kind of recommendations/ best
> > practices can you offer to ensure maximum HDD life? What are some
> > warning signs we should look for, other than 'my drive has come to a
> > literal screeching halt'? SMART is nifty, but in my experience has
> > only warned me of problems after I knew there were problems. What can
> > I do to detect a drive failure before it occurs, and to get my data
> > off before the drive becomes unreadable?
>
> First, a question. What's the current philosophy on spinning down
> drives? Is it better or worse for longevity that keeping them spinning
> and idle? I've got my recordings spread across a bunch of drives, 5
> are exclusively used by myth, with a spin-down time of about 20
> minutes. Given the typical myth usage, these can stay spun down for hours.
>

spinning up is the hardest thing for the little motor to do, the more you do 
it the more it will put wear on the motor's windings. As well, spinning up 
takes a lot of energy, which heats the motor windings causing the wear, but 
also using this extra amount of energy. In fact, when rebooting a computer, 
its actually better to not let the harddrive platters come to a stop before 
repowering them, because if you repower while they still have some inertia 
you significantly reduce the amount of energy the motor requires to start 
spinning the platters.

Now, for example, on a laptop, its actually better to leave the harddrive 
spinning than to have it put the harddrive to sleep after a few minutes of 
inactivity. I don't know what the equal energy point is, but considering the 
wear and tear as well, I feel its safer to set the harddrive sleep time on a 
laptop running on batteries at the ~10minute area.

For desktops (which only get powered on when needed and don't run 24/7) I 
suggest never letting the drive go to sleep, the cost for the power to leave 
the drive spinning is minimal compared to the wear and tear on the motor. It 
should also be noted that desktop motors are much more robust than laptop 
motors, so they can endure many more starts.

For a computer constantly running like our MythTV systems, I would use a 
thought process similar to the laptop one...
Considering most shows are based on 30minute "blocks" you would want to set 
your sleep time on a multiple of 30 and based on your recording habits. for 
example, if you do most of your recordings during primetime with no more than 
1 hour in between recordings, set your harddrive sleep time to just over an 
hour (1hr5mins for example), this way you prevent the drive from going to 
sleep between recordings, but after the final recording for the evening, and 
final viewings, it will go to sleep overnight.

Hope this helps,
Steve