summary

create raid tool at linux

A Quick Summary of raidreconf

History:
Raidreconf was originally written by Jakob Oestergaard in 1999.  This package 
could convert between any block device and a Software RAID-0 array.  Convert 
includes growing and shrinking as well.

The RAID-5 code was written by Daniel S. Cox in 2001.  With the excellent 
framework Jakob had provided, the integration was easy.  The hardest part was
understanding the framework from the source.

Capability:
Raidreconf can grow, shrink, and/or convert between RAID-0 and RAID-5
arrays and simple block devices.  It converts between RAID arrays in-place,
and thus saves one-half of a potentially long copy in/copy out process.

Caveats:
Raidreconf has been tested some, but not extensively yet.  Use with caution!
One concern is the lack of a restart capability.  If a conversion fails due
to power loss, or a disk failure, you're hosed!

Note:
A conversion that results in a RAID-5 array does not calculate the parity
blocks during the conversion.  The MD super-blocks are marked dirty, and
the parity blocks are all calculated after the conversion ends.  Of course,
the array can be used straight-away, with a slight performance penalty.