atacontrol and creating raid-1 arrays

Søren Schmidt sos at
Tue Sep 14 02:39:41 PDT 2004

Eirik Oeverby wrote:
>> Since the RAID metadata has to be put on disk it wont work if you have 
>> that area used for real data. Depending on what controller you use the 
>> metadata can be stored in different places. Other than that it works 
>> if you are *sure* the disks are identical (dd with a decnet blocksize 
>> is *much* faster tha cp).
> Yea, I used dd (blocksize 256kbyte proved optimal; ~40mbyte/sec) for my 
> final operation; was testing with cp first to make sure. This is a 
> Silicon Image SATA RAID controller which isn't supported by the ATA 
> driver in RAID mode, so it's purely software. Which, according to 
> another reply I got, uses the last 255 sectors on the disk. These were 
> already free, so I just tested - seems to work fine. Fsck has no 
> complaints. Other things I should do to verify?

The Silicon Image SATA "RAID" controller is supported by ATA, and it has 
*NO* RAID capabilities whatsoever, its all done in software, I just dont 
support the particular metadata format that your BIOS uses.
Now that said metadata can take anywhere from 1 to 17 sectors either in 
the front (old HPT) or the end (Promise/LSI/native) of the disk.
Anyhow if ataraid picks it up etc you should be fine :)


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