RAID 0+1

Jeff Vian jvian10 at charter.net
Tue Mar 21 14:00:24 UTC 2006


On Tue, 2006-03-21 at 15:52 +1100, jakosalem at telpacific.com.au wrote:
> Hello All,
> 
> I've been googling the past couple of weeks to find a solution to my
> problem. Obviously I have not been successful. I really need a solution
> fast.
> 
> I'm currently setting up a new server with 8X73 SCSI disks. I want to
> implement RAID 0+1 (create a RAID 1 array from a pair of RAID 0s with 3
> disks each). I'm currenly running Fedora Core 4 with the latest updates. I
> have been trying to do this but to no avail.
> 
Why not raid 5?  The available space is n-1 for the number of drives
used.  A single drive failure does not impact function at all because of
the redundancy and parity stripe that keeps all data intact.

Raid 0+1 gives at best n/2 space and means you only have 3*73 or a total
of 219gb available.  A single disk problem takes out the entire mirror
copy (3 disks) because of striping.  A data error on one copy and any
other error (even in a different location) on the second copy will take
everything out (again because of the striping effect of raid 0). 

The same 6 drives in raid 5 would give you 5*73 or 365gb of space and a
single drive failure would not in any way harm your data. The redundant
drive feature would keep everything working while the one drive is
replaced.

If I have the option I would personally never recommend a raid 10
configuration.

> I think I read somewhere that Fedora Core 4 still has no support for this.
> Is this correct? Will Fedora Core 5 solve my problem? Can anyone help me
> out on the steps needed to create a RAID 10 setup?
> 
> Really need help.
> 
> TIA,
> 
> Edward
> 
> 
> 




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