LVM, RAID

[Michael Hipp]

I'm hoping someone can tutor me...

I need to build a box with a goodly amount of storage. It will use an eclectic mix of different disks. It needs to be growable by adding more disks. It needs to have RAIDesque fault tolerance.

The fault tolerance can be supplied by RAID5. The growable feature can be supplied by LVM. And this seems to be the Standard Google Answer (tm) - LVM on top of RAID5.

The MDs can't themselves grow. The LVs can grow, but only by addition of another MD. So growth consists of minimally three disks as an MD. And those three disks must be essentially identical and hopefully not all attached to the same controller and power supply. This makes every increment quite expensive and bothersome.

I want to be able to grow one disk at a time. Is this possible?

Thanks,
Michael