ataraid and 1TB+ storage?

[Dimitry Andric]

On 2004-11-23 at 22:43:41 Daniel Eriksson wrote:

> ad4: 190782MB <ST3200822A/3.01> [387621/16/63] at ata2-master UDMA100
> ad5: 190782MB <ST3200822A/3.01> [387621/16/63] at ata2-slave UDMA100
> ad6: 190782MB <ST3200822A/3.01> [387621/16/63] at ata3-master UDMA100
> ad7: 190782MB <ST3200822A/3.01> [387621/16/63] at ata3-slave UDMA100
> ad8: 190782MB <ST3200822A/3.01> [387621/16/63] at ata4-master UDMA100
> ad9: 190782MB <ST3200822A/3.01> [387621/16/63] at ata4-slave UDMA100
[...]
> ar0: 9007199253788533MB <ATA RAID0 array> [1499975777/255/63] status: READY

This looks like a wraparound over 2^31 sectors, so the sector count
gets negative.  And then this is interpreted as a 64-bit unsigned:

(2^64 - (6*387621*16*63 - 2^31)) / 2 / 1024 = 9007199254644874 MB

Not exactly, but close enough to the reported 9007199253788533 MB, I
would think...  If anyone can explain the difference, please let us
know.  (I'm guessing that the LBA capacity of the individual drives is
a bit different from the 387621/16/63 geometry they're reporting.)

Anyway, this is probably some bug in the ataraid driver. :)
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