No subject

as two individual local disks, and fast enough.

> While it stinks to miss your favorite show, or even a couple of
> them... the cost of a RAID array (even software RAID) far exceeds
> the loss.

With software RAID its just the cost of disks and the time it takes to
set it up, and if you count your time for real, you wouldn't be using
mythtv in the first place. :-)

And disks are still fairly cheap. Whether they're worth it,
well, depends, I guess.

> > RAID can also give serious performance boost

> It is false that RAID gives you a performance boost.

In the specific context of mythtv, agreed.

> No RAID array can sustain transfers faster than the transfer rate of
> the individual drives combined.

That is obvious, but it doesn't mean RAID can't boost performance.

> Where RAID is faster is doing single operations.

In general, it can be faster whenever the number of disks exceeds the
number of simultaneous operations. Note: _can_ be, it may well be
slower as well, sometimes by design - e.g., RAID5 and RAID6 are
notoriously slow in writing.

> Rarely, such as when concurrent recordings seem to all be going to
> the same disk (because of the logic behind the storage group load
> balancing) a RAID array would have the advantage... but MOST of the
> time, the load is spread pretty equally, so I am getting better
> performance than what RAID can offer.

Yes, given that disks are so fast that a single disk is always fast
enough for one recording, by a huge margin.
And while, say, a 4-disk RAID10 array would be faster for two parallel
recordings than four independent disks (two of them would be idle),
it does not seem likely that there'll be any super-HD format in the near
future where that'd matter. :-)

-- 
Tapani Tarvainen