Re: Is this enough for us to have triple-parity RAID?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


On 04/17/2012 01:18 PM, David Brown wrote:
> 
> For quad parity, we can try g3 = 8 as the obvious next choice in the
> pattern.  Unfortunately, we start hitting conflicts.  To recover missing
> data, we have to solve multiple simultaneous equations over G(2⁸), whose
> coefficients depend on the index numbers of the missing disks.  With
> parity generators (1, 2, 4, 8), some of these combinations of missing
> disk indexes lead to insoluble equations when you have more that 21 disks.
> 

That is because 255 = 3*5*17... this means {02}^3 = {08} is not a generator.

	-hpa

--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[ATA RAID]     [Linux SCSI Target Infrastructure]     [Managing RAID on Linux]     [Linux IDE]     [Linux SCSI]     [Linux Hams]     [Device-Mapper]     [Kernel]     [Linux Books]     [Linux Admin]     [Linux Net]     [GFS]     [RPM]     [git]     [Photos]     [Yosemite Photos]     [Yosemite News]     [AMD 64]     [Linux Networking]

Add to Google Powered by Linux