[mythtv-users] Mirroring root partition on SSD to a hard drive -- bad idea?

[Ben Kamen]

On 2016-01-16 5:02 AM, Simon Hobson wrote:
> Gary Buhrmaster <gary.buhrmaster at gmail.com> wrote:
>
>> There is, of course, another lesson here.  Your
>> "on-site <cold> spare" is not a spare unless
>> you have at least run it "hot" for some (short)
>> period of time.
> Indeed.
>
> And there's two things there.
> One issue with raid is that usually all the drives are bought at the same time - and there's a good chance that they'll all come from the same batch (exposing you to batch-specific manufacturing issues).
> So you take several drives, potentially from the same batch, and run them for the same duty cycle/loading - and hope that they'll all fail at substantially different times ! You certainly hope that when one drive fails, the rest last sufficiently longer for you to replace the failed one and rebuild it. Given that some arrays can have rebuild times going out to many hours or even days ...
> And if you run with a hot spare, then it was probably from the same batch, and has been installed and powered up (even if it's not been working) for the same time as the working drives.
>
> So IMO, there's an argument for building an array with different models of drives - ie no two drives identical.
>
> But like everything in life, there's no right or wrong answer to that.
>

Yep - thought about all that too.

Technically speaking, 2 drives were purchased at the same time (the original 2) and the spare was purchased about a month later.

But yes -- all those things float around in my head.

Can make a blond guy dizzy I tell ya. ;)