Adding a disk to ReadyNAS Pro for RAID5/6 volume expansion?

chirpa wrote:
http://www.readynas.com/RAIDiator_x86_4_2_16_Notes

OK, it almost worked. I upgraded to 4.2.16 and then the volume tabs for both of my volumes had a section listing the new disk 5, and a new checkbox to add it to the volume. I actived the one for Volume C (RAID6), and before rebooting, had a look at the tab for Volume D. The checkbox was grayed out, so I thought I had to do the expansion one after the other.

After the reboot Volume C was successfully expanded to span all 5 disks. But now the tab for Volume D no longer had the section listing the new disk 5, and no chance to add anything to it.

I had a look at the logs. The partition tables for disks 1-4 have:

Number  Start (sector)    End (sector)  Size       Code  Name
   1               4         8388611   4.0 GiB     FD00  Linux RAID
   2         8388612         9437187   512.0 MiB   FD00  Linux RAID
   3         9437188       442189827   206.4 GiB   FD00  Linux RAID
   4       442189828      3907026947   1.6 TiB     FD00  Linux RAID

and disk 5 has:

Number  Start (sector)    End (sector)  Size       Code  Name
   1              64         8388671   4.0 GiB     FD00  Linux RAID
   2         8388672         9437247   512.0 MiB   FD00  Linux RAID
   3         9437248       442189887   206.4 GiB   FD00  

so there is a slight difference, but still room for that extra partition to add to Volume D, but how can I tell it do to so? :(