Re: md faster than h/w?

[Max Waterman <davidmaxwaterman+gmane@fastmail.co.uk>]

Michael Tokarev wrote:
> Max Waterman wrote:
> []
>> My preference will probably be raid10 - ie raid0 2 drives, raid0
>> another 2 drives, and then raid1 both raid0s. My 5th disk can be a hot
>> spare. Round reasonable?
> 
> Nononono. Never do that.  Instead, create two raid1s and raid0
> both, ie, just the opposite.  Think about the two variants, and
> I hope you'll come to the reason why raid0(2x raid1) is more
> reliable than raid1(2x raid0). ;)

Ah, yes. Right. I was aware of the 'difference', just had it backwards
in my mind...oops.

> 
>> Alternatively, we could probably get a 6th disk and do raid1 on
>> disk #5 & #6 and install the OS on that - keeping the application
>> data separate. This would be ideal, I think. For some reason, I like
>> to keep os separate from application data.
> 
> BTW, there's a raid10 module in current 2.6 kernels, which works
> somewhat differently compared with raid0(2x raid1) etc.

oh? and how does that compare to the MD. Although I can create md devices
using mdadm, I guess I'm not completely sure what actually does the work.

Max.