Re: [gentoo-user] Re: How can I power disk off?

[Paul Hartman <paul.hartman+gentoo@gmail.com>]

On Thu, Oct 6, 2011 at 8:29 PM, Grant Edwards <grant.b.edwards@gmail.com> wrote:
> On 2011-10-06, Jarry <mr.jarry@gmail.com> wrote:
>> Hi,
>>
>> In my server I have a few disks which must be running 24/7,
>> but I also have a single big hard-drive, which is used only
>> for a few minutes every day, just for backups. How could I
>> power disk off when not needed (and "on" again when needed)
>> in order to save a little power and prolong its life?
>
> That prompts one to ask the question:  Does spinning a drive up/down
> every day lengthen or shorten it's life compared to having it on 24/7
> (assuming the same number of seeks in both cases).

I think it is generally believed that by NOT spinning down the drive,
you are going to shorten its life-span. Any HDD made in the past few
years are designed with spin-up/spin-down when idle in mind.
Constantly spinning will probably wear it out faster than regularly
spinning up and down. It should be able to handle thousands of
spin-up/spin-down cycles with ease. I think SMART will tell you how
many times it has happened.

In my case I disabled it because I found it to be annoying and
inappropriate for my RAID, but I realize I'm wasting power and
probably jeopardizing the long-term health of my drives by not
allowing them to spin-down.