[CentOS] RAID 5 setup?

Sat Mar 27 09:07:18 UTC 2010
John R Pierce <pierce at hogranch.com>

Robert Spangler wrote:
> On Thursday 25 March 2010 18:10, Robert Heller wrote:
>
>   
>>  The prefered way to go would be RAID10 (RAID1 (mirror) + RAID0 (stripe)).
>>  Form pairs as RAID1, then strip the pairs.  With 8 disks, this would 4
>>  pairs, 1.5TB/pair = 1.5*4 = 6TB total.
>>     
>
> I am just starting to look into this RAID and I was wondering wouldn't RAID01 
> be better then RAID10?  In a 4 disc system having the first two using 
> stripping and then backing them up the second set with mirrors?
>
> My though is having D1 and D2 as the primary drives stripping and then having 
> D3 backup D1 and D4 backup D2.
>
> And if enough room place a couple more drives in the system as hot standby's.
>
> Or am I looking at this all wrong?
>   


for all practical purposes its the same thing.     if it was really 
stripe then mirror, a naive mirror handler would think it would have to 
remirror both drives when one half of one of the stripesets failed and 
was replaced.     but in fact, the mirror handlres tend to be well aware 
of whats going on.      mirror 0+1  aand stripe that with mirrored 2+3, 
and its really all the same    the native raid10 in newer mdraid is 
cleaner because you don't end up with extra partial volume metadevices...