[linux-lvm] About Extending LVM size with Hardware Raid

[Chris Cox]

Vahric MUHTARYAN wrote:
> 	Okey you mean create a new raid5 with new disks and add it to volume
> group okey you right . 
> 
> 	But My question is , Think that I have raid5 array with 3 disk ( I'm
> using ICP Raid controller card )  then I add 4.th disk to my raid array ( I
> know clearly that I can extend raid5 ) at this I have more disk space but I
> have to intorduce it to system , and I can't imagine How ?! it's easy if I
> have free partiton but I can't show this extended array like a free
> partition  :( 

If you truly can "extend raid5", you have a totally different disk
essentially.  It's nice that you have a HW raid that allows you to
extend RAID 5 (an icky mess for sure.. probably takes a while to
do the reshuffling).  I don't know how to tell LVM that the disk itself
has actually gotten bigger.  Interesting problem, I doubt there's
an answer for this though (but I could be wrong).

I think if I wanted an extensible array setup, I would consider
just aggregating a set of mirror'd drives into a volume group.
That way, I could just add two more disks, create a new hw logical
raid 1 drive, and add that to my volume group.  Something I will
consider doing.