RAID0 to RAID5 upgrade

[Bill Davidsen <davidsen@tmr.com>]

I have three drives, with some various partitions, currently set up like 
this.

  drive0    drive1    drive2

   hdb1      hdi1      hdk1
   \_________RAID1________/

   hdb2      hdi2      hdk2
  unused     \___RAID0____/
   200GB       100GB x 2

             hdi3      hdk3
             \___unused___/
                100GB x 2

What I want to have is 3 x 200 = 400GB RAID5.

I would like to avoid copying 200GB of data to another machine and back 
if I can do the conversion. Since mdadm does handle --level= with grow, 
I assume I have to create another RAID0 from hd[ik]3, copy the data 
there, delete the array using hd[ik]2, create a new RAID5 to use 
hd[bik]2, copy the data from the temporary array to the new RAID5 array, 
delete the hd[ik]3 partitions, grow the hd[bik]2 partitions, grow the 
array, and if I didn't miss a step be done :-(

Is there a better way? Copy over a network or restore are going to be 
very slow.

-- 
bill davidsen <davidsen@tmr.com>
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979