Re: Data recovery from linear array (Intel SS4000-E)

[Johannes Moos <jmoos@gmx.de>]

Hi Phil,
thanks for your help!

On 13.10.2011 23:09, Phil Turmel wrote:
> You *do* understand that "linear" has *no* redundancy? If you can't 
> read anything at all off the bad drive, that fraction of your data is 
> *gone*. As a linear array, files that are entirely allocated on the 
> other three are likely to be recoverable. 
Yes, 500GB are gone for sure. It's just about recovering what's left on 
the three working drives.
> Create a zeroed placeholder file for the missing drive (must be exactly the right size):
>
> dd if=/dev/zero of=Disk2_Partition3.fake bs=512 count=624353185
OK, one 500GB drive is dead (I had 2x320GB and 2x500GB), so I modified 
the line to
dd if=/dev/zero of=Disk2_Partition3.fake bs=512 count=$((499703758848/512))
because Partition 3 on that drive was 499703758848 bytes
> mdadm --create --metadata=0.90 --level=linear -n 4 /dev/md0 /dev/loop{0,1,2,3}
I think I need --chunk=64 as well because mdadm defaults to 512kb and 
the Intel box uses 64kb?
http://www.intel.com/support/motherboards/server/ss4000-e/sb/CS-029880.htm

Best regards,
Johannes Moos